vitamin B12 Archives - Health Tips From The Professor

What Nutrients Are Missing In Prenatal Supplements?

May 7, 2024 by Dr. Steve Chaney

Do These Deficiencies Matter?

Author: Dr. Stephen Chaney

If you are a pregnant mom, nothing is more important than the health of your baby. And if you are pregnant or thinking of becoming pregnant, your doctor has probably recommended a prenatal supplement. But does the prenatal supplement he or she recommended provide you with all the nutrients you need?

In a previous issue of “Health Tips From the Professor” I shared two studies that suggested the answer is, “No”. Those studies concluded that most prenatal supplements had little or no vitamin K, choline, DHA, and iodine – all of which are essential for the health of your newborn baby. And while most prenatal supplements contained calcium, the amount they provided was far below recommended levels.

The authors of the first study also made the point that most women going on a prenatal supplement will probably discontinue taking their multivitamin supplement, so a good prenatal supplement should provide all the essential nutrients.

But they don’t. Folic acid, iron, calcium, and vitamin D have long been recognized as essential for a healthy pregnancy. So, virtually every prenatal supplement contained these four nutrients, although calcium is often present in suboptimal amounts. Beyond those four nutrients, the design of prenatal supplements is haphazard. Some contain vitamin K, choline, iodine, or DHA (often in suboptimal amounts). But almost none contain all four nutrients.

And when you consider the other essential nutrients you find in most multivitamins, prenatal supplements often come up empty. Is that a problem? That’s what this study (KM Godfrey et al, PLOS Medicine, 1-27, December 5, 2023) was designed to find out.

How Was This Study Done?

This was a double-blind, placebo-controlled clinical trial, the gold standard for clinical studies. The investigators recruited 1,729 women who were planning to get pregnant from England, Singapore, and New Zealand between 2015 and 2017.

The women were randomly split into two groups:

The control group received a supplement containing nutrients that were most frequently included in prenatal supplements in those countries (folic acid, iron, calcium, iodine, and beta-carotene).

The intervention group received a supplement containing those nutrients plus riboflavin, vitamin B6, vitamin B12, vitamin D, zinc, inositol, and probiotics).

Riboflavin, vitamin B6, vitamin B12, vitamin D, and zinc were included because they are included in most multivitamins but are often missing in prenatal supplements.

Inositol was included because some studies have suggested that inositol may reduce the risk of maternal hyperglycemia and gestational diabetes.

Blood samples to assess nutritional status were obtained from all women in the study before the trial started (baseline) and after 1 month of supplementation with either the control or intervention formulation.

Of the women entering the study, 512 went on to have a singleton (one child) pregnancy. For these women supplementation was continued until childbirth. Additional blood samples were obtained in early and late pregnancy and at 6 months postdelivery. [Note: no supplementation was provided to either group postdelivery. And this is also a period of time when most women would be breastfeeding.]

The blood samples were tested for:

Blood levels of folic acid, riboflavin, vitamin B6, vitamin B12, and vitamin D.

Functional biomarkers of deficiencies of each of these vitamins.

What Nutrients Are Missing In Prenatal Supplements?

There was no difference in maternal hyperglycemia or gestational diabetes between the control group and the intervention group supplemented with inositol, so I will focus on the other nutrients present in the intervention group.

At baseline when subjects were first entered into the study.

29.2% of the subjects had low or marginal status for folic acid.

82.0% of the subjects had low or marginal status for riboflavin.

1.3% of the subjects had low or marginal status for vitamin B6.

9.1% of the subjects had low or marginal status for vitamin B12.

48.7% of the subjects had low or marginal status for vitamin D.

91.0% of the subjects had low or marginal status for one or more of these vitamins.

In the control group receiving folic acid but no riboflavin, vitaminB6, vitamin B12, and vitamin D:

Folic acid deficiency fell to 4.1% after 1 month of supplementation (the supplement used by the control group contained folic acid), 1% in early pregnancy, 6.1% in late pregnancy, and rose to 31.8% 6 months after supplementation was discontinued. The intervention group got the same amount of folic acid, and their results were similar.

Riboflavin deficiency ranged from 82-92% during pregnancy and returned to 82% 6 months postdelivery.

Vitamin B6 deficiency increased to 54% in late pregnancy and returned to 1.2% 6 months postdelivery.

Vitamin B12 deficiency increased to 55% in late pregnancy and returned to 12.4% 6 months postdelivery.

Vitamin D deficiency ranged from 35-43% during pregnancy and returned to 31% 6 months postdelivery.

Functional markers of vitamin B6 deficiency were evident by late pregnancy.

In short, data from the control group fell into 3 categories:

The data with folic acid confirm previous studies showing that folic acid in the amount present in most prenatal supplements is effective at preventing folic acid deficiency before and during pregnancy. It also strengthens the argument for continuing folic acid supplementation during breastfeeding.

Deficiencies of riboflavin and vitamin D are prevalent in women of childbearing age, but pregnancy does not appear to significantly impact the percentage of women who are deficient in these nutrients.

Deficiencies of vitamins B6 and B12 are rare in women of childbearing age, but pregnancy significantly depletes both nutrients.

- This was particularly evident for vitamin B6. Blood levels of vitamin B6 markers decreased to a level that could impact the functioning of vitamin B6-depended metabolic pathways.

For the intervention group receiving additional riboflavin, vitamin B6, vitamin B12, and vitamin D:

Deficiencies of these vitamins were eliminated by one month of supplementation.

Vitamin levels remained adequate during pregnancy.

Except for vitamin B12, deficiencies of these vitamins reappeared when supplementation was discontinued for 6 months. The maintenance of adequate B12 levels 6 months after supplementation stopped was expected because the body holds on to its B12 stores very tightly.

In short deficiencies of these nutrients before and during pregnancy could be eliminated by supplementation with levels of these nutrients found in many multivitamins.

The authors concluded, “Over 90% of the trial participants had low concentrations of one or more of folate, riboflavin, vitamin B12, or vitamin D during preconception, and many developed markers of vitamin B6 deficiency in late pregnancy. Preconception/pregnancy supplementation in amounts available in over-the-counter supplements substantially reduces the prevalence of vitamin deficiency and depletion markers before and during pregnancy, with higher maternal plasma vitamin B12 maintained during the recommended lactation period.”

Do These Deficiencies Matter?

It is well established that deficiencies of folic acid and vitamin D cause health risks for the mother and developmental risks for the fetus, so I won’t discuss these nutrients here.

However, the effect of riboflavin, vitamin B6, and vitamin B12 deficiencies on pregnancy is less well known, which is probably why these nutrients are often not added to prenatal supplements.

The authors of the study said small studies have suggested that:

Low or deficient riboflavin status may be associated with a higher risk of anemia during pregnancy.

Low vitamin B6 status may be associated with an increased risk of preterm birth and development of metabolic health risks in the child.

Low vitamin B12 status may be associated with increased risk of gestational diabetes and pre-eclampsia in the mother, and increased risk of neural tube defects, preterm birth, low birth weight, and neurocognitive delays in the baby – with the strongest evidence being an effect on neurocognitive development.

While none of these risks have been definitively proven, the authors point out that deficiencies of these nutrients can easily be eliminated with inexpensive, over-the-counter multivitamin supplements.

What Does This Study Mean For You?

Perhaps I should start this section by asking why these deficiencies are so common in women of child-bearing age.

The authors speculate that part of the reason is that many women are giving up meat (B12 and iron) and dairy (calcium and riboflavin) for health or environmental reasons.

However, they also point out that a more likely cause is that more than 60% of calories consumed in countries like England, New Zealand, and the United States comes from ultra-processed foods – otherwise known as “empty calories”.

Whatever the cause, the authors conclude, “…the findings suggest a need to reappraise dietary recommendations for preconception and pregnancy to consider further the role of multiple micronutrient supplements for women living in higher-income countries.” I agree.

In a previous “Health Tips From the Professor” article, I reported a recent study showing that most prenatal supplements have either no or inadequate amounts of vitamin K, choline, DHA, iodine, and calcium, nutrients that are absolutely essential for a healthy pregnancy. And I gave recommendations for choosing the best prenatal supplement for you and your child.

That study also noted that many women discontinue their multivitamin supplement when they start taking a prenatal supplement. The current study indicates that practice may be unwise. It shows that:

Many women of childbearing age are deficient in one or more of these essential nutrients, and…

Essential nutrients not found in most prenatal supplements may also be important for a healthy pregnancy.

So, if you are pregnant or thinking of becoming pregnant, follow this article’s recommendation to start with a well-designed prenatal supplement that provides adequate amounts of folate, iron, calcium, vitamin D, vitamin K, choline, DHA, and iodine and add a multivitamin supplement that provides the other essential nutrients. Alternatively, a simpler approach would be to choose a well-designed prenatal supplement that includes all the essential nutrients. That would be my recommendation.

I would also note this study showed that deficiencies of most of these nutrients reappeared as soon as supplementation was discontinued. Although the authors of this study did not mention it, this reinforces the importance of continuing supplementation during breastfeeding.

The Bottom Line

I have previously reported on a study that concluded many prenatal supplements lack one or more nutrients shown to be important for a healthy pregnancy. But let’s say you have found a prenatal supplement that provides all those nutrients. Is that enough?

Studies show that most women stop taking their multivitamin supplement when they start on a prenatal supplement. But is that a good idea? Are there essential nutrients found in multivitamins, but not in many prenatal supplements that are also important for a healthy pregnancy?

A recent study asked that question in women who were trying to become pregnant. The study found that:

Many women of childbearing age are deficient in one or more essential nutrients found in multivitamin supplements but often missing in prenatal supplements, and…

Essential nutrients not found in most prenatal supplements may also be important for a healthy pregnancy.

For more details about this study and what it means for you read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

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My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

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About The Author

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years. Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Are Vegan Diets Bad For Your Bones?

May 25, 2021 by Dr. Steve Chaney

The Secrets To A Healthy Vegan Diet

Author: Dr. Stephen Chaney

Osteoporosis is a debilitating and potentially deadly disease associated with aging. It affects 54 million Americans. It can cause debilitating back pain and bone fractures. 50% of women and 25% of men over 50 will break a bone due to osteoporosis. Hip fractures in the elderly due to osteoporosis are often a death sentence.

As I discussed in a previous issue of “Health Tips From The Professor”, a “bone-healthy lifestyle requires 3 essentials – calcium, vitamin D, and weight bearing exercise. If any of these three essentials is presence in inadequate amounts, you can’t build healthy bones. In addition, other nutrients such as protein, magnesium, zinc, vitamin B12, and omega-3 fatty acids may play supporting roles.

Vegan and other plant-based diets are thought to be very healthy. They decrease the risk of heart disease, diabetes, and some cancers. However, vegan diets tend to be low in calcium, vitamin D, zinc, vitamin B12, protein, and omega-3 fatty acids. Could vegan diets be bad for your bones?

A meta-analysis of 9 studies published in 2009 (LT Ho-Pham et al, American Journal of Clinical Nutrition 90: 943-950, 2009) reported that vegans had 4% lower bone density than omnivores, but concluded this difference was “not likely to be clinically relevant”.

However, that study did not actually compare bone fracture rates in vegans and omnivores. So, investigators have followed up with a much larger meta-analysis (I Iguacel et al, Nutrition Reviews 77, 1-18, 2019) comparing both bone density and bone fracture rates in vegans and omnivores.

How Was This Study Done?

The investigators searched the literature for all human clinical studies through November 2017 that compared bone densities and frequency of bone fractures of people consuming vegan and/or vegetarian diets with people consuming an omnivore diet.

Vegan diets were defined as excluding all animal foods.

Vegetarian diets were defined as excluding meat, poultry, fish, seafood, and flesh from any animal but including dairy foods and/or eggs. [Note: The more common name for this kind of diet is lacto-ovo vegetarian, but I will use the author’s nomenclature in this review.]

Omnivore diets were defined as including both plant and animal foods from every food group.

The investigators ended up with 20 studies that had a total of 37,134 participants. Of the 20 studies, 9 were conducted in Asia (Taiwan, Vietnam, India, Korea, and Hong-Kong), 6 in North America (the United States and Canada), and 4 were conducted in Europe (Italy, Finland, Slovakia, and the United Kingdom).

Are Vegan Diets Bad For Your Bones?

Here is what the investigators found:

Bone density: The clinical studies included 3 different sites for bone density measurements – the lumbar spine, the femoral neck, and the total body. When they compared bone density of vegans and vegetarians with the bone density of omnivores, here is what they found:

Lumbar spine:

- Vegans and vegetarians combined had a 3.2% lower bone density than omnivores.

- The effect of diet was stronger for vegans (7% decrease in bone density) than it was for vegetarians (2.3% decrease in bone density).

Femoral neck:

- Vegans and vegetarians combined had a 3.7% lower bone density than omnivores.

- The effect of diet was stronger for vegans (5.5% decrease in bone density) than it was for vegetarians (2.5% decrease in bone density).

Whole body:

- Vegans and vegetarians combined had a 3.2% lower bone density than omnivores.

- The effect of diet was statistically significant for vegans (5.9% decrease in bone density) but not for vegetarians (3.5% decrease in bone density). [Note: Statistical significance is not determined by how much bone density is decreased. It is determined by the size of the sample and the variations in bone density among individuals in the sample.]

Bone Fractures: The decrease in bone density of vegans in this study was similar to that reported in the 2009 study I discussed above. However, rather than simply speculating about the clinical significance of this decrease in bone density, the authors of this study also measured the frequency of fractures in vegans, vegetarians, and omnivores. Here is what they found.

Vegans and vegetarians combined had a 32% higher risk of bone fractures than omnivores.

The effect of diet on risk of bone fractures was statistically significant for vegans (44% higher risk of bone fracture) but not for vegetarians (25% higher risk of bone fractures).

These data suggest the decreased bone density in vegans is clinically significant.

The authors concluded, “The findings of this study suggest that both vegetarian and vegan diets are associated with lower bone density compared with omnivorous diets. The effect of vegan diets on bone density is more pronounced than the effect of vegetarian diets, and vegans have a higher fracture risk than omnivores. Both vegetarian and vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.”

The Secrets To A Healthy Vegan Diet

The answer to this question lies in the last statement in the author’s conclusion, “Both vegetarian and vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.”

The problem also lies in the difference between what a nutrition expert considers a vegan diet and what the average consumer considers a vegan diet. To the average consumer a vegan diet is simply a diet without any animal foods. What could go wrong with that definition? Let me count the ways.

Sugar and white flour are vegan. A vegan expert thinks of a vegan diet as a whole food diet – primarily fruits, vegetables, whole grains, beans, nuts, and seeds. A vegan novice includes all their favorites – sodas, sweets, and highly processed foods. And that may not leave much room for healthier vegan foods.

2) Big Food, Inc is not your friend. Big Food tells you that you don’t need to give up the taste of animal foods just because you are going vegan. They will just combine sugar, white flour, and a witch’s brew of chemicals to give you foods that taste just like your favorite meats and dairy foods. The problem is these are all highly processed foods. They are not healthy. Some people call them “fake meats” or “fake cheeses”. I call them “fake vegan”.

If you are going vegan, embrace your new diet. Bean burgers may not taste like Big Macs, but they are delicious. If need other delicious vegan recipe ideas, I recommend the website https://forksoverknives.com.

3) A bone healthy vegan diet is possible, but it’s not easy. Let’s go back to the author’s phrase “…vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.” A vegan expert will do the necessary planning. A vegan novice will assume all they need to do is give up animal foods.

As I said earlier, vegan diets tend to be low in calcium, vitamin D, zinc, vitamin B12, protein, and omega-3 fatty acids. Let’s look at how a vegan expert might plan their diet to get enough of those bone-healthy nutrients.

- Calcium. The top plant sources of calcium are leafy greens and soy foods at about 100-250 mg (10-25% of the DV) of calcium per serving. Some beans and seeds are moderately good sources of calcium. Soy foods are a particularly good choice because they are a good source of calcium and contain phytoestrogens that stimulate bone formation.

A vegan expert makes sure they get these foods every day and often adds a calcium supplement.

- Protein. Soy foods, beans, and some whole grains are the best plant sources of protein.

It drives me crazy when a vegan novice tells me they were told they can get all the protein they need from broccoli and leafy greens. That is incredibly bad advice.

A vegan expert makes sure they get soy foods, beans, and protein-rich grains every day and often adds a protein supplement.

- Zinc. There are several plant foods that supply around 20% the DV for zinc including lentils, oatmeal, wild rice, squash and pumpkin seeds, quinoa, and black beans.

A vegan expert makes sure they get these foods every day and often adds a multivitamin supplement containing zinc.

- Vitamin D and vitamin B12. These are very difficult to get from a vegan diet. Even vegan experts usually rely on supplements to get enough of these important nutrients.

4) Certain vegan foods can even be bad for your bones. I divide these into healthy vegan foods and unhealthy “vegan” foods.

- Healthy vegan foods that can be bad for your bones include.

- - Pinto beans, navy beans, and peas because they contain phytates.

- - Raw spinach & swiss chard because they contain oxalates.

- - Both phytates and oxalates bind calcium and interfere with its absorption.

- - These foods can be part of a healthy vegan diet, but a vegan expert consumes them in moderation.

- Unhealthy “vegan” foods that are bad for your bones include sodas, salt, sugar, and alcohol.

- - The mechanisms are complex, but these foods all tend to dissolve bone.

- - A vegan expert minimizes them in their diet.

5) You need more than diet for healthy bones. At the beginning of this article, I talked about the 3 essentials for bone formation – calcium, vitamin D, and exercise. You can have the healthiest vegan diet in the world, but if you aren’t getting enough weight bearing exercise, you will have low bone density. Let me close with 3 quick thoughts:

- None of the studies included in this meta-analysis measured how much exercise the study participants were getting.

- The individual studies were generally carried out in industrialized countries where many people get insufficient exercise.

- The DV for calcium in the United States is 1,000-1,200 mg/day for adults. In more agrarian societies dietary calcium intake is around 500 mg/day, and osteoporosis is almost nonexistent. What is the difference? These are people who are outside (vitamin D) doing heavy manual labor (exercise) in their farms and pastures every day.

In summary, a bone healthy vegan lifestyle isn’t easy, but it is possible if you work at it.

The Bottom Line

A recent meta-analysis asked two important questions about vegan diets.

Do vegans have lower bone density than omnivores?

2) Is the difference in bone density clinically significant? Are vegans more likely to suffer from bone fractures?

The study found that:

Vegans had 5.5%–7% lower bone density than omnivores depending on where the bone density was measured.

Vegans were 44% more likely to suffer from bone fractures than omnivores.

The authors of the study concluded, ““The findings of this study suggest that…vegan diets are associated with lower bone density compared with omnivorous diets, and vegans have a higher fracture risk than omnivores…Vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.”

In evaluating the results of this study, I took a detailed look at the pros and cons of vegan diets and concluded, “A bone healthy vegan lifestyle isn’t easy, but it is possible if you work at it.”

For more details about study and my recommendations for a bone healthy vegan lifestyle read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Do Supplements Interfere With Chemotherapy?

February 2, 2021 by Dr. Steve Chaney

Should You Avoid Supplement Use During Chemotherapy?

Since much of my research career was devoted to cancer research, specifically developing new chemotherapeutic drugs for treating cancer, many of you have asked me the question: “Do food supplements interfere with chemotherapy?”

My answer has always been that it is theoretically possible, but that we don’t really know the answer because the necessary studies have not been done.

However, I do know that most cancer drugs are retained in the body for a short period of time. So, my pragmatic advice has always been to avoid supplementation for a day or two before to a day or two after each round of chemotherapy. That is a strategy designed to minimize the possibility that supplementation would interfere with chemotherapy and maximize the possibility that supplementation might aid in recovery between rounds of chemotherapy.

That is why I was interested when I saw the recent headlines claiming certain supplements may interfere with chemotherapy for breast cancer. I wanted to find out if someone had finally done a definitive study on the effect of supplementation on chemotherapy.

So, I have reviewed the study (CB Ambrosone et al, Journal of Clinical Oncology, 38, 804-815, 2020) behind the headlines and will share what I discovered.

How Was The Study Done?

This study was an offshoot of a much larger Phase III clinical trial designed to determine the best schedule for administering three drugs (doxorubicin, cyclophosphamide, and paclitaxel) to patients with high-risk early-stage breast cancer.

The 1,134 patients enrolled in this study were given questionnaires on their use of supplements when they registered for the study to determine supplement use prior to the study. They were also given questionnaires when they completed chemotherapy to determine supplement use during chemotherapy.

The questionnaires documented use of:

Multivitamins

The antioxidants vitamin C, vitamin A, vitamin E, carotenoids, and coenzyme Q10.

Vitamin D.

The B vitamins vitamin B6, vitamin B12, and folic acid.

The minerals iron and calcium.

Omega-3 fatty acids.

Glucosamine, melatonin, and acidophilus.

Recurrence of the breast cancer and death from breast cancer were measured 6 months after chemotherapy ended.

Do Supplements Interfere With Chemotherapy?

The study reported:

The number of patients using individual antioxidant supplements was too low to determine whether individual antioxidants had any effect on treatment outcomes.

When the patients using any antioxidant supplement were pooled into a single group, there was a nonsignificant association between antioxidant supplement use during chemotherapy and an increased risk of breast cancer recurrence and death from breast cancer.

Iron use during chemotherapy was significant associated with an increased risk of breast cancer recurrence.

Vitamin B12 use during chemotherapy was significantly associated with increased risk of breast cancer recurrence and death from breast cancer.

Multivitamin use was not associated with either recurrence or death from breast cancer.

The number of patients using the other supplements was too low to determine whether those supplements had any effect on treatment outcomes.

The authors concluded: “Associations between survival outcomes and use of antioxidant and other dietary supplements are consistent with recommendations for caution among patients when considering the use of supplements, other than a multivitamin, during chemotherapy.”

This is the conclusion that generated the headlines you may have seen.

However, in their discussion the authors conceded that a previous review concluded that, “…insufficient evidence existed with regard to the safety of dietary supplements [during chemotherapy] to make recommendations, and that still may be the case.”

I will discuss the reasons for their disclaimer below. However, I will point out that disclaimers like this never seem to make it into the headlines you read.

What Are The Strengths And Weaknesses Of This Study?

The only strength of this study is that it was performed in the context of an ongoing clinical trial, with surveys conducted before chemotherapy and during chemotherapy to assess supplement use.

However, the study had multiple weaknesses that limit the ability to draw any firm conclusions from the study.

#1: The number of people using supplements in this study was very small. For example:

Only 200 people took any antioxidants during chemotherapy.

Only 137 people took a vitamin B12 supplement during chemotherapy.

Only 109 people took an iron supplement during chemotherapy.

To put this into perspective, if a drug company were submitting a new drug for approval to the FDA, they would be required to submit data from ~50-100-fold more cancer patients to prove that the drug was effective.

With this small number of supplement users, even “statistically significant” observations are questionable.

In contrast, the number of people taking a multivitamin during chemotherapy was 497. Thus, those data were a little stronger than the data for individual supplements.

#2: They did not ask why people were taking supplements. It turns out that the patients who used supplements were older and sicker. They were more likely to be overweight and to have type 2 diabetes.

These are patients who are also more likely to have poor outcomes from chemotherapy. The authors tried to correct for that, but it is virtually impossible to make these corrections when the number of patients taking supplements is so low.

#3: They did not ask about the dose of supplements people were taking.

Multivitamins typically contain RDA levels of antioxidants and vitamin B12, so it would be safe to assume that RDA levels of antioxidants and vitamin B12 are safe during chemotherapy.

Approximately 50% of the women in the study were premenopausal, so it is likely that they were taking a multivitamin with iron. That suggests that RDA levels of iron are safe during chemotherapy for premenopausal women.

In short, the association between supplement use and poorer outcomes from chemotherapy is tenuous. If there is any association, it is likely with high dose individual supplements rather the lower levels of the same nutrients found in a multivitamin.

Is An Effect Of Supplement Use On Chemotherapy Plausible?

As a biochemist, the next question I ask is whether there is a plausible mechanism for an effect of any of these supplements on chemotherapy outcomes.

For two of the drugs in the regimen (paclitaxel and cyclophosphamide), free radical formation may contribute to their effectiveness, but it is not their main mechanism of action. Thus, it is plausible that high dose antioxidant supplements could make these drugs less effective, but the effect should be relatively small.

Tumors require high amounts of iron for proliferation, so it is plausible that excess iron could make tumors more resistant to chemotherapy. However, for premenopausal women, multivitamins with iron did not interfere with the drugs used in this study. Thus, it appears likely that RDA levels of iron, where appropriate, do not interfere with chemotherapy.

The authors said that the reason for the observed effects of vitamin B12 on chemotherapy in their study “remains to be understood”. However, the answer might be found in the dosage of vitamin B12. A previous study reported that doses of vitamin B12 that were greater than 20 times the RDA increased the risk of lung cancer.

If people in this study were taking doses of vitamin B12 in excess of 20 times the RDA, it would provide a plausible explanation for B12 interfering with chemotherapy. If not, there is no known explanation. In any case, I do not recommend taking such high doses of any supplement.

Should You Avoid Supplement Use During Chemotherapy?

Now, let’s get back to the original question: “Should you avoid supplement use during chemotherapy?” If you read the headlines saying, “Supplement Use During Chemotherapy May Be Risky”, you might think that the answer is an unqualified yes. That is also what your doctor is likely to think.

However, when you analyze the study behind the headlines you realize that the evidence supporting the headlines is very weak.

So, that puts us back to where we were before the study was published. Simply put:

It is theoretically possible that supplements interfere with chemotherapy, but we don’t know for sure.

A pragmatic approach is to avoid supplementation for a day or two before to a day or two after each round of chemotherapy. This is a strategy designed to minimize the possibility that supplementation would interfere with chemotherapy and maximize the possibility that supplementation might aid in recovery between rounds of chemotherapy.

Note: This is generic advice. I am not a medical doctor, so it would be unethical for me to provide individualized advice on how to minimize interactions between supplements and chemotherapy. What I recommend is that you ask your doctor whether my generic recommendations make sense for your cancer and your drug regimen.

If this study advanced our knowledge at all, it would be that:

The supplements most likely to interfere with chemotherapy appear to be high dose antioxidants, vitamin B12, and iron supplements.

Multivitamins, even multivitamins with iron when appropriate, are unlikely to interfere with chemotherapy.

The Bottom Line

Recent headlines have warned, “Supplement Use During Chemotherapy May Be Risky”. Is that true?

However, when you analyze the study behind the headlines you realize that the evidence supporting the headlines is very weak.

So, that puts us back to where we were before the study was published. Simply put:

It is theoretically possible that supplements interfere with chemotherapy, but we don’t know for sure.

A pragmatic approach is to avoid supplementation for a day or two before to a day or two after each round of chemotherapy. This is a strategy designed to minimize the possibility that supplementation would interfere with chemotherapy and maximize the possibility that supplementation might aid in recovery between rounds of chemotherapy.

Note: This is generic advice. I am not a medical doctor, so it would be unethical for me to provide individualized advice on how to minimize interactions between supplements and the chemotherapy drugs you are on. What I recommend is that you ask your doctor whether my generic recommendations make sense for your cancer and your drug regimen.

If this study advanced our knowledge at all, it would be that:

The supplements most likely to interfere with chemotherapy appear to be high dose antioxidants, vitamin B12, and iron supplements.

Multivitamins, even multivitamins with iron when appropriate, are unlikely to interfere with chemotherapy.

For more details read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Will Non-GMO Foods Be Less Nutritious?

March 4, 2014 by Dr. Steve Chaney

The Unintended Consequences of the Proposed Non-GMO Labeling Laws

Author: Dr. Stephen Chaney

Post Foods recently announced that their Grape Nuts cereal will be completely non-GMO. General Foods followed suit by announcing that their Original Cheerios will also be non-GMO. That’s good news, right?

Maybe, but it turns out that the new non-GMO Grape Nuts will no longer contain vitamins A, D, B12 or riboflavin, and the amount of riboflavin in a serving of Cheerios decreased from 25% of the daily recommended value (DV) to 2% of the DV.

The cereal manufacturers claim that their new cereals are more wholesome, but one nutrition expert said “The new products are arguably less healthy given their lower vitamin content.”

I’ve never been one to claim that throwing a few vitamins into a serving of cereal turns it into a nutrition powerhouse, but the decreased vitamin content of the new non-GMO cereals does raise a few questions.

Why were the vitamins removed?

Did it have anything to do with the cereals being non-GMO?

Does this mean that the non-GMO processed foods of the future will be less nutritious than the foods they replace?

The cereal manufacturers were mum when asked these questions, so we will need to rely on some scientific sleuthing and a bit of intuition to get the answers.

The Flaw in The Proposed Non-GMO Labeling Laws

I first discussed this topic a few months ago in a “Health Tips From The Professor” article titled “When is GMO Non-GMO?” I received a lot of irate comments from people who take every word on the non-GMO websites and videos as the gospel truth. (The professor has never been one to shy away from controversy when he sees claims that aren’t based on good science.)

However, I think my article was misunderstood by some of my readers, so let me review my conclusions briefly:

There are definitely environmental concerns around the widespread use of GM crops – especially those that allow heavy pesticide and herbicide usage.

There are potential health concerns related to the consumption of unprocessed GM foods and proteins derived from GM foods – although those heath concerns have been blown way out of proportion in the media.

If the proposed Non-GMO labeling laws stopped there, they would be scientifically justified. But they go one step further by requiring that processed foods labeled as non-GMO cannot contain any ingredient obtained from a GM source. There is no scientific justification for this.

Nutrients (sugars, oils & vitamins) derived from GM sources are chemically and biologically indistinguishable from those same nutrients derived from non-GMO sources.

The intentions of the proposed non-GMO labeling laws are good, but whenever you go beyond what good science supports there are often unintended consequences – such as the vitamin-depleted non-GMO cereals that the food manufacturers have just announced.

Will Non-GMO Foods Be Less Nutritious?

To understand the answer to that question, let’s look at what probably happened to the vitamins in the non-GMO cereals.

In today’s world many vitamins are purified from genetically modified microorganisms – bacteria & yeast that have been modified to overproduce certain vitamins. In evaluating the significance of that statement, here are a few facts to consider:

1) We have gotten vitamins from these sources for many years.

B vitamins have been obtained from yeast for at least a hundred years.

A significant portion of the vitamins we absorb on a daily basis are made by bacteria in our gut.

2) The only difference today is that these microorganisms have been genetically modified to overproduce the vitamins.

3) These are naturally sourced vitamins.

The microorganisms are the same ones that have provided these vitamins for generations.

The enzymes used by the microorganisms to make the vitamins are the same.

4) There is no downside to the use of GM organisms as a source of natural vitamins.

There is no environmental risk from the use of these GM microorganisms. They don’t contain any dangerous genes that could wreak havoc if they escaped from the food processing plants.

Because the purified vitamins are indistinguishable from those obtained from non-GMO sources, there are also no health risks.

5) The advantage of using these GM organisms is clear. It substantially lowers the cost of vitamins and allows them to be used in the mass market – for example, in popular breakfast cereals.

6) Most food manufacturers can’t simply use non-GMO sourced vitamins and raise their prices.

A recent poll showed that 53% of Americans prefer non-GMO foods, but only 11% are willing to pay more for those foods

What Does the Future Hold?

Even though they are scientifically flawed, the proposed non-GMO labeling laws will probably become the law in several states in the near future. (Good science has never played much of a role in political decisions.)

Currently, there simply aren’t enough non-GMO vitamins available to supply the mass market – even if price were no concern. So, in the short term, many non-GMO processed foods are likely to be less nutritious than the foods they will replace – as we just saw with Grape Nuts and Cheerios.

However, most people feel that American ingenuity and the law of supply and demand will eventually result in a bigger supply of reasonable priced non-GMO vitamins. When that happens non-GMO processed foods will be just as nutritious as the older GM versions.

However, at this point nobody knows how long that will take.

The Bottom Line:

1) There is a scientific basis for environmental and potential health concerns regarding genetically modified whole foods and the protein extracted from these foods.

2) However, proposed non-GMO labeling laws would require that a processed food be labeled as genetically modified if it contains any nutrient purified from a genetically modified organism.

3) There is no scientific justification for this requirement. Purified vitamins from GM and non-GM microorganisms are chemically and biologically indistinguishable. Furthermore, the GM microorganisms used to produce the vitamins pose no environmental or health risks.

4) Non-GMO vitamins (vitamins prepared from non-GMO microorganisms) are currently in short supply and are very expensive compared to vitamins prepared from GM microorganisms.

5) Consequently, the unintended consequence of these proposed non-GMO labeling laws will likely be that many of the new non-GMO processed foods will contain fewer vitamins and, therefore, will be less nutritious than the foods they replace – at least in the short term. The new non-GMO Grape Nuts and Cheerios may be just the tip of the iceberg.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.