Are Vitamin D Supplements Worthless?

Written by Dr. Steve Chaney on . Posted in Vitamin D Supplements

Are We Asking The Right Question?

Author: Dr. Stephen Chaney

 

are vitamin d supplements worthlessWe have been told that vitamin D is a miraculous “must have” vitamin. We have been told it’s not just important for healthy bones. It’s also important for a strong immune system, heart health, protection from cancer, and many other health benefits. We have been told that we should get our 25-hydroxy vitamin D levels tested and supplement with extra vitamin D if they are low.

Now, the latest headlines are saying all of that is wrong. They are telling us vitamin D supplements do not improve bone density or protect against falls and bone fractures. They are telling us to forget all the other claimed benefits of vitamin D. Those claims have been disproved. Forget about the 25-hydroxy vitamin D tests. They are a waste of money.

What is the truth? Why is it so confusing? Are vitamin D supplements worthless?  Let me guide you through the claims and counterclaims so you can discover the truth for yourself.

How Did Vitamin D Become So Popular?

are vitamin d supplements worthless popularLet’s start with a brief history of vitamin D. It all started with the industrial revolution in Northern Europe. Suddenly, children and adults in the large cities were spending the bulk of their waking hours in dark factories rather than outdoors on the farm. They were already living in northern latitudes where sunlight was weak during the winter months. To make matters worse pollution from the factories was creating a haze that blocked the sunlight.

That lead directly to the discovery that sunlight was crucial to our body’s ability to synthesize vitamin D and that vitamin D was essential for building strong bones. The solution to the public health crisis of rickets and osteomalacia was to fortify dairy products with vitamin D. The almost universal adaptation of vitamin D fortification virtually eliminated rickets and osteomalacia except in association with certain rare diseases. The two important lessons learned from this experience were:

  • Vitamin D is essential for healthy bone formation.
  • Vitamin D supplementation improves bone health for individuals who are deficient in vitamin D

As we discuss the latest findings, we need to keep in mind that these fundamental principles have not changed.

In the late 20th century our understanding of vitamin D took another leap with the discovery that vitamin D receptors were not restricted to bone cells. Almost every cell in our body contained vitamin D receptors. That lead to studies showing that people with low vitamin D intakes were more likely to experience heart disease, cancer, some autoimmune diseases, and infectious diseases such as flu than people with high vitamin D intakes.

The final leap in our understanding of vitamin D took place when the medical profession started routinely testing blood levels of 25-hydroxy vitamin D. That is when we discovered that some people who appeared to have adequate intake of vitamin D and/or adequate exposure to sunlight had low blood levels of 25-hydroxy vitamin D. Furthermore, follow-up studies showed that low 25-hydroxyvitamin D levels correlated with an increased risk of heart disease, cancer, and infectious disease. The important lessons learned from these experiments were:

  • Vitamin D deficiency is associated with increased risk of multiple diseases.
  • 25-hydroxy vitamin D tests are the best way to measure vitamin D deficiency.

Once again, these fundamental principles have not changed.

What Did The Study Show?

are vitamin d supplements worthless studyThe study (MJ Bolland et al, Lancet Diabetes Endocrinology 2018) behind the headlines was a meta-analysis of 81 randomized, placebo-controlled studies with a total of 53,537 subjects that looked at the effect of vitamin D supplementation in elderly populations on bone mineral density, bone fractures, and falls.

The meta-analysis only included studies in which vitamin D intake was the sole variable. In many cases the subjects were not taking a calcium supplement. If they were taking a calcium supplement, both the vitamin D group and placebo group were taking the same amount of calcium.

 

The results were unequivocal. In this study vitamin D supplementation had no effect on bone mineral density, bone fractures, or falls in elderly populations. The authors concluded “There is little justification to use vitamin D supplements to maintain or improve musculoskeletal health.”

 

Is this conclusion justified? Let’s put the findings of this study into a broader perspective.

 

Are We Asking The Right Questions?

are vitamin d supplements worthless holistic approachBefore throwing out our vitamin D supplements let’s ask whether this study is asking the right question. I have covered this topic in detail in my new book “Slaying The Supplement Myths” (https://slayingthesupplementmyths.com) with respect to similar studies that had called into question the value of calcium supplements for bone health. Let me cover the highlights here.

In my book I created the graphic on the right to put the question of who benefits from supplementation into perspective. For the purposes of this discussion, I will just focus on poor diet (or, in the case of vitamin D, poor exposure to sunlight). As I discussed above, science shows that people who are not getting enough vitamin D from diet and sunlight benefit from vitamin D supplementation. Unfortunately, vitamin D enthusiasts and some supplement companies have muddied the waters by going beyond what good science shows and suggesting or implying that everyone will benefit from vitamin D supplementation.

This is part of the problem. Once you have created a paradigm that everyone will benefit from vitamin D supplementation, that paradigm is easy to disprove. If someone already has adequate, or nearly adequate, levels of 25-hydroxy vitamin D, would we expect additional vitamin D to make a difference? Of course not, but that is exactly the question the most recent study was asking.

In discussing the limitations of their study, the authors said: “It is possible that trials of populations with low baseline 25-hydroxy vitamin D might produce different results because only 4 trials, involving 831 participants (1.6% of all participants), reported mean baseline 25-hydroxy vitamin D levels lower than 25 nmol/L (the level indicating vitamin D deficiency).

In other words, the study did not measure the effect of vitamin D supplementation for people who were vitamin D deficient. The only take-home lesson from this study is that people with adequate, or near adequate, vitamin D status do not benefit from vitamin D supplementation. That is a “no-brainer.”

 

Vitamin D And A Bone Healthy Lifestyle

are vitamin d supplements worthless garbage in outThe other glaring deficiency of this study is that it was only measuring the effect of vitamin D on bone health. They purposely excluded any other factor that might influence bone health. That was a fatal flaw because healthy bone requires a holistic approach, not individual nutrients. In my book Slaying the Supplement Myths  I refer to this as a “bone healthy lifestyle.”

The most important feature of a “bone healthy lifestyle” is this:

  • Calcium, vitamin D, and resistance (weight bearing) exercise are all essential for healthy bones.
  • However, none of them is sufficient by itself. You need all three. You need a holistic approach if you wish to build strong bones.

Simply put, that means unless you include adequate calcium and exercise there is no reason to expect vitamin D supplementation to help build strong bones. Unfortunately, none of the studies included in the recent meta-analysis took a holistic approach to bone health. Some included calcium, but many didn’t. Resistance exercise was never considered. The studies were doomed to failure.

When you include flawed studies in your meta-analysis, you have what computer programmers call “Garbage in. Garbage out.” A meta-analysis can never be stronger than the individual studies it includes.

Other features of a “bone healthy lifestyle” include:

  • We need more than calcium and vitamin D for strong bones. We need magnesium, zinc, copper, manganese, vitamin C and vitamin K. If we are deficient in any of these, calcium will not be utilized as efficiently.
  • The foods we eat are also important. Our bones serve as a buffer system to keep our bodies slightly alkaline. Every time we eat acid-forming foods a little bit of bone is dissolved to neutralize the acid. For optimal bone health we need to minimize acid-forming foods and eat more alkaline-forming foods. That means we need to avoid sodas, sweets and refined grains. We also need to minimize meats, eggs, and dairy. Instead, we should focus on fruits, vegetables, peas, beans, lentils, seeds, and nuts.
  • Beware of drugs. The list of common medications that dissolve bones is a long one. Some of the worst offenders are anti-inflammatory steroids such as cortisone and prednisone, drugs to treat depression, drugs to treat acid reflux, and excess thyroid hormone. I am not suggesting that you should avoid properly prescribed medications. I would suggest you ask your doctor or pharmacist whether the drugs you are taking adversely affect bone density. If they do, you should pay a lot more attention to the other aspects of a “bone healthy lifestyle.”

 

Are Vitamin D Supplements Worthless?

are vitamin d supplements worthless bone healthNow we can come back to the question “Are vitamin D supplements worthless?” as the recent headlines have suggested. If you phrase the question as “Does everyone benefit from vitamin D supplementation?” or “Is vitamin D supplementation alone sufficient to build strong bones?” the answer is a clear no.

However, those are the wrong questions. If you ask: “Does vitamin D supplementation benefit people who are vitamin D-deficient?” the answer is a clear yes. If you ask: “Does a holistic approach that includes resistance exercise, adequate calcium, and adequate vitamin D improve bone health?” the answer is likely to be yes as well.

What about the headlines claiming that vitamin D is also worthless for strengthening the immune system and reducing the risk of heart disease, cancer, and auto-immune diseases?  The studies on which these claims are based suffer from the same flaws. They are asking the same wrong questions.

My recommendations:

  • Have your blood levels of 25-hydroxy vitamin D tested on a regular basis. I have them tested each year when I get my physical.
  • If your blood levels of 25-hydroxy vitamin D are below 25 nmol/L (which the NIH considers deficient), you are likely to benefit from vitamin D supplementation. If they are above 50 nmol/L (which the NIH considers sufficient), vitamin D supplementation is unlikely to provide additional benefit. However, that level of vitamin D doesn’t guarantee that you will have strong bones. You also need sufficient calcium and resistance exercise.
  • If your blood levels are in the insufficient range (between 25 nmol/L and 50 nmol/L), the situation is more complicated. If you are close to 50 nmol/L, you may benefit slightly from adding a vitamin D supplement, but the benefit will be too small to show up in a clinical study such as the one that resulted in the recent headlines. My advice is to look at your diet and medication use. If they put you at risk for low bone density, my recommendation would be to add a vitamin D supplement – along with adequate calcium and resistance exercise, of course. If you are closer to 25 nmol/L, you will likely benefit from a vitamin D supplement along with adequate calcium and exercise.
  • Don’t think of vitamin D supplementation as a “magic bullet” that will solve all your ills. Instead, think of it as just one component of a holistic approach to a bone healthy lifestyle.

 

The Bottom Line

 

A recent meta-analysis concluded that vitamin D supplementation did not improve bone mineral density, reduce bone fractures, or reduce falls in the elderly. While this conclusion was definitive, the study was asking the wrong questions.

  • We know that vitamin D improves bone health for people who are vitamin D-deficient. However, only 1.6% of the people in this study were vitamin D-deficient at the beginning of the study. That means the study was really asking: “If people have adequate, or near adequate, vitamin D status, does vitamin D supplementation provide any additional benefit?”  The answer to that question is a “no-brainer.”  There is no reason to expect that additional vitamin D would provide benefit.
  • We know that while vitamin D is essential for building strong bones, it is not sufficient by itself. Strong bones require a holistic approach that includes resistance exercise, adequate calcium, and adequate vitamin D. However, this study only looked at the effect of vitamin D on bone health. Calcium and exercise were excluded from consideration. That means the study was really asking: “Is vitamin D a “magic bullet” that can build strong bones by itself?” Again, there is no reason to expect vitamin D to provide much benefit under those conditions.

My recommendations:

  • Have your blood levels of 25-hydroxy vitamin D tested on a regular basis. I have them tested each year when I get my physical.
  • If your blood levels of 25-hydroxy vitamin D are low, you are likely to benefit from vitamin D supplementation. If they are already optimal, vitamin D supplementation is unlikely to provide additional benefit.
  • Don’t think of vitamin D supplementation as a “magic bullet” that will keep your bones strong by itself. Instead, think of it as just one component of a holistic “bone healthy lifestyle.”

 

For more details and to see my detailed recommendations, 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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Comments (2)

  • Jo Anne

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    Very informative with great backup to information.

    Reply

  • Pat

    |

    Thank you Dr. Chaney, Its much cleaner now.
    Pat

    Reply

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Latest Article

A Low Carb Diet and Weight Loss

Posted January 15, 2019 by Dr. Steve Chaney

Do Low-Carb Diets Help Maintain Weight Loss?

Author: Dr. Stephen Chaney

 

low carb dietTraditional diets have been based on counting calories, but are all calories equal? Low-carb enthusiasts have long claimed that diets high in sugar and refined carbs cause obesity. Their hypothesis is based on the fact that high blood sugar levels cause a spike in insulin levels, and insulin promotes fat storage.

The problem is that there has been scant evidence to support that hypothesis. In fact, a recent meta-analysis of 32 published clinical studies (KD Hall and J Guo, Gastroenterology, 152: 1718-1727, 2017 ) concluded that low-fat diets resulted in a higher metabolic rate and greater fat loss than isocaloric low-carbohydrate diets.

However, low-carb enthusiasts persisted. They argued that the studies included in the meta-analysis were too short to adequately measure the metabolic effects of a low-carb diet. Recently, a study has been published in the British Medical Journal (CB Ebbeling et al, BMJ 2018, 363:k4583 ) that appears to vindicate their position.

Are low carb diets best for long term weight loss?

Low-carb enthusiasts claim the study conclusively shows that low-carb diets are best for losing weight and for keeping it off once you have lost it. They are saying that it is time to shift away from counting calories and from promoting low-fat diets and focus on low-carb diets instead if we wish to solve the obesity epidemic. In this article I will focus on three issues:

  • How good was the study?
  • What were its limitations?
  • Are the claims justified?

 

How Was The Study Designed?

low carb diet studyThe investigators started with 234 overweight adults (30% male, 78% white, average age 40, BMI 32) recruited from the campus of Framingham State University in Massachusetts. All participants were put on a diet that restricted calories to 60% of estimated needs for 10 weeks. The diet consisted of 45% of calories from carbohydrate, 30% from fat, and 25% from protein. [So much for the claim that the study showed low-carb diets were more effective for weight loss. The diet used for the weight loss portion of the diet was not low-carb.]

During the initial phase of the study 161 of the participants achieved 10% weight loss. These participants were randomly divided into 3 groups for the weight maintenance phase of the study.

  • The diet composition of the high-carb group was 60% carbohydrate, 20% fat, and 20% protein.
  • The diet composition of the moderate-carb group was 40% carbohydrate, 40% fat, and 20% protein.
  • The diet composition of the low-carb group was 20% carbohydrate, 60% fat, and 20% protein.

Other important characteristics of the study were:

  • The weight maintenance portion of the study lasted 5 months – much longer than any previous study.
  • All meals were designed by dietitians and prepared by a commercial food service. The meals were either served in a cafeteria or packaged to be taken home by the participants.
  • The caloric content of the meals was individually adjusted on a weekly basis so that weight was kept within a ± 4-pound range during the 5-month maintenance phase.
  • Sugar, saturated fat, and sodium were limited and kept relatively constant among the 3 diets.

120 participants made it through the 5-month maintenance phase.

 

Do Low-Carb Diets Help Maintain Weight Loss?

low carb diet maintain weight lossThe results were striking:

  • The low-carb group burned an additional 278 calories/day compared to the high-carb group and 131 calories/day more than the moderate-carbohydrate group.
  • These differences were even higher for those individuals with higher insulin secretion at the beginning of the maintenance phase of the study.
  • These differences lead the authors to hypothesize that low-carb diets might be more effective for weight maintenance than other diets.

 

What Are The Pros And Cons Of This Study?

low carb diet pros and consThis was a very well-done study. In fact, it is the most ambitious and well-controlled study of its kind. However, like any other clinical study, it has its limitations. It also needs to be repeated.

The pros of the study are obvious. It was a long study and the dietary intake of the participants was tightly controlled.

As for cons, here are the three limitations of the study listed by the authors:

#1: Potential Measurement Error: This section of the paper was a highly technical consideration of the method used to measure energy expenditure. Suffice it to say that the method they used to measure calories burned per day may overestimate calories burned in the low-carb group. That, of course, would invalidate the major findings of the study. It is unlikely, but it is why the study needs to be repeated using a different measure of energy expenditure.

#2: Compliance: Although the participants were provided with all their meals, there was no way of being sure they ate them. There was also no way of knowing whether they may have eaten other foods in addition to the food they were provided. Again, this is unlikely, but cannot be eliminated from consideration.

#3: Generalizability: This is simply an acknowledgement that the greatest strength of this study is also its greatest weakness. The authors acknowledged that their study was conducted in such a tightly controlled manner it is difficult to translate their findings to the real world. For example:

  • Sugar and saturated fat were restricted and were at very similar levels in all 3 diets. In the real world, people consuming a high-carb diet are likely to consume more sugar than people in the other diet groups. Similarly, people consuming the low-carb diet are likely to consume more saturated fat than people in the other diet groups.
  • Weight was kept constant in the weight maintenance phase by constantly adjusting caloric intake. Unfortunately, this seldom happens in the real world. Most people gain weight once they go off their diet – and this is just as true with low-carb diets as with other diets.
  • The participants had access to dietitian-designed prepared meals 3 times a day for 5 months. This almost never happens in the real world. The authors said “…these results [their data] must be reconciled with the long-term weight loss trials relying on nutrition education and behavioral counseling that find only a small advantage for low carbohydrate compared with low fat diets according to several recent meta-analyses.” [I would add that in the real world, people do not even have access to nutritional education and behavioral modification.]

 

low carb diet and youWhat Does This Study Mean For You?

  • This study shows that under very tightly controlled conditions (dietitian-prepared meals, sugar and saturated fat limited to healthy levels, calories continually adjusted so that weight remains constant) a low-carb diet burns more calories per day than a moderate-carb or high-carb diet. These findings show that it is theoretically possible to increase your metabolic weight and successfully maintain a healthy weight on a low-carb diet. These are the headlines you probably saw. However, a careful reading of the study provides a much more nuanced viewpoint. For example, the fact that the study conditions were so tightly controlled makes it difficult to translate these findings to the real world.
  • In fact, the authors of the study acknowledged that multiple clinical studies show this almost never happens in the real world. These studies show that most people regain the weight they have lost on low-carb diets. More importantly, the rate of weight regain is virtually identical on low-carb and low-fat diets. Consequently, the authors of the current study concluded “…translation [of their results to the real world] requires exploration in future mechanistic oriented research.” Simply put, the authors are saying that more research is needed to provide a mechanistic explanation for this discrepancy before one can make recommendations that are relevant to weight loss and weight maintenance in the real world.
  • The authors also discussed the results of their study in light of a recent, well-designed 12-month study (CD Gardener et al, JAMA, 319: 667-669, 2018 ) that showed no difference in weight change between a healthy low-fat versus a healthy low-carbohydrate diet. That study also reported that the results were unaffected by insulin secretion at baseline. The authors of the current study noted that “…[in the previous study] participants were instructed to minimize or eliminate refined grains and added sugars and maximize intake of vegetables. Probably for this reason, the reported glycemic load [effect of the diet on blood sugar levels] of the low-fat diet was very low…and similar to [the low-carb diet].” In short, the authors of the current study were acknowledging that diets which focus on healthy, plant-based carbohydrates and eliminate sugar, refined grains, and processed foods may be as effective as low-carb diets for helping maintain a healthy weight.
  • This would also be consistent with previous studies showing that primarily plant-based, low-carb diets are more effective at maintaining a healthy weight and better health outcomes long-term than the typical American version of the low-fat diet, which is high in sugar and refined grains. In contrast, meat-based, low-carb diets are no more effective than the American version of the low-fat diet at preventing weight gain and poor health outcomes. I have covered these studies in detail in my book “Slaying The Food Myths.”

Consequently, the lead author of the most recent study has said: “The findings [of this study] do not impugn whole fruits, beans and other unprocessed carbohydrates. Rather, the study suggests that reducing foods with added sugar, flour, and other refined carbohydrates could help people maintain weight loss….” This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.

The Bottom Line

 

  • A recent study compared the calories burned per day on a low-carb, moderate-carb, and high-carb diet. The study concluded that the low-carb diet burned significantly more calories per day than the other two diets and might be suitable for long-term weight control. If confirmed by subsequent studies, this would be the first real evidence that low-carb diets are superior for maintaining a healthy weight.
  • However, the study has some major limitations. For example, it used a methodology that may overestimate the benefits of a low-carb diet, and it was performed under tightly controlled conditions that can never be duplicated in the real world. As acknowledged by the authors, this study is also contradicted by multiple previous studies. Further studies will be required to confirm the results of this study and show how it can be applied in the real world.
  • In addition, the kind of carbohydrate in the diet is every bit as important as the amount of carbohydrate. The authors acknowledge that the differences seen in their study apply mainly to carbohydrates from sugar, refined grains, and processed foods. They advocate diets with low glycemic load (small effects on blood sugar and insulin levels) and acknowledge this can also be achieved by incorporating low-glycemic load, plant-based carbohydrates into your diet. This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.
  • Finally, clinical studies report averages, but none of us are average. When you examine the data from the current study, it is evident that some participants burned more calories per hour on the high-carb diet than other participants did on the low carb diet. That reinforces the observation that some people lose weight more effectively on low-carb diets while others lose weight more effectively on low-fat diets. If you are someone who does better on a low-carb diet, the best available evidence suggests you will have better long-term health outcomes on a primarily plant-based, low-carb diet such as the low-carb version of the Mediterranean diet.

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.

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