Vitamin D and Multiple Sclerosis | Preventive Care?

Written by Dr. Steve Chaney on . Posted in current health articles, Vitamins and Health

Author: Dr. Stephen Chaney

 

vitamin d and multiple sclerosisA new study (Mokry et al, PLOS Medicine, DOI: 10.1371/journal.pmed.1001866, August 25, 2015) suggests that people who are genetically prone to low vitamin D levels are at increased risk of developing multiple sclerosis (MS). To understand the importance of this study and what it means for us, we need to first review what is already known about vitamin D and multiple sclerosis.

  • MS is an autoimmune disease in which the immune system attacks the myelin sheath that coats our nerves. Conceptually, that’s the equivalent of a fraying cord on a lamp. Eventually, the cord is going to start shorting out and the lamp won’t work very well. On a very basic level MS is similar. As our myelin sheath is damaged over time, our nervous system starts working less well.
  • The earliest evidence that vitamin D status might be associated with MS was the observation that the prevalence of MS was highest for people who lived in northern regions with little exposure to sunlight.
  • Numerous studies since then have shown that MS patients generally have lower 25-hydroxy vitamin D levels in their blood.

These studies clearly show an association between low vitamin D status and MS, but association does not prove causation. There are two limitations of association studies that significantly reduce their predictive value – reverse causation and confounding factors.Those are both somewhat highfalutin scientific terms, so let me put them in plain English – and in terms that are relevant to our discussion of vitamin D status and MS.

Reverse causation simple means that the MS might have caused low vitamin D status. For example, individuals with MS might spend less time outdoors because of their physical limitations. That would result in less sun exposure, which would decrease their blood levels of 25-hydroxy vitamin D.

A confounding factor would be something else that increased the risk for MS and happened to be associated with low vitamin D status. Suppose, for example, that exercise decreased the risk of MS. People who spend most of their time inside in front of a TV or computer screen would have low levels of exercise and low sun exposure. If it was the lack of exercise rather than the low vitamin D status that actually predisposed to MS, lack of exercise would be a confounding factor for any clinical study comparing vitamin D status with risk of developing MS.

 

What Can Genetics Tell Us About The Relationship Between Vitamin D and Multiple Sclerosis?

does-vitamin-d-prevent-msThe authors of this study had previously identified mutations in 4 genes that decrease blood levels of 25-hydroxy vitamin D (the most commonly used measure of vitamin D status). In this study(Mokry et al, PLOS Medicine, DOI: 10.1371/journal.pmed.1001866, August 25, 2015)they analyzed the frequency of those genetic mutations in 14,498 MS cases compared with 24,091 healthy controls. Their study showed:

  • Genetic mutations that decrease 25-hydroxy vitamin D levels are associated with a significant increase in the risk of developing MS.
  • Based on the relationship of those mutations with 25-hydroxy vitamin D levels, they calculated that every 50% increase in 25-hydroxy vitamin D levels was associated with a 50% decreased risk of developing MS.

This was a very large, well designed study. It has some limitations of its own, but because it used a genetic approach it largely avoids the concern about reverse causation and confounding factors. In short, this study strongly supports the conclusion from previous studies that low vitamin D status significantly increases the risk of developing MS.

The authors concluded “The identification of vitamin D as a causal susceptibility factor for MS may have important public health implications, since vitamin D insufficiency is common, and vitamin D supplementation is both relatively safe and cost effective.”

 

Is Vitamin D Supplementation Effective In Preventing And Treating MS?

Vitamin DThe authors of the study also concluded “These findings provide the rationale for further investigating the therapeutic benefits of vitamin D supplementation in preventing the onset and progression of MS.”

While more studies are still needed, the Nurses’ Health Study (Munger et al, Neurology, 62: 60-65, 2004) provides pretty convincing evidence that vitamin D supplementation can prevent the onset of MS. That study followed 187,563 nurses for at least 4 years, during which time 173 of them developed MS. The study showed that supplementation with 400 IU/day of vitamin D reduced the risk of developing MS by 40%.

The efficacy of vitamin D supplementation in preventing the progression of MS is much less well established. Several studies have shown that low vitamin D status is associated with higher levels MS relapse and more rapid progression of MS symptoms.However, studies of vitamin D supplementation conducted to date have been too small and too short in duration to be definitive.

What Is The Significance Of This Study?

On one hand MS is a very rare disease, affecting around 0.1% of the adult population. On the other hand, it is a debilitating disease. If something as simple as assuring adequate vitamin D status can reduce the risk of developing MS by 40-50%, it is an important public health measure, especially since 40% of the US population has insufficient blood levels of vitamin D (Looker et al, American Journal of Clinical Nutrition, 88: 1519-1527, 2008).

What Does This Study Mean For You?

SunWhat does this study mean for you and me? We already know that adequate vitamin D status is essential for building strong bones, and there is pretty good evidence that adequate vitamin D status is important for a strong immune system. Now we can add autoimmune diseases to the list. It is pretty clear that adequate vitamin D status is important for preventing MS. It may help prevent other autoimmune diseases as well.

One interesting wrinkle for MS is that it may be vitally important to assure adequate vitamin D in our younger years. Studies looking at people who grow up in northern latitudes and then move south and vice versa suggest that the risk of developing MS is much more strongly associated with sun exposure during the first 10-15 years of life than with sun exposure later in life.

It is, therefore, not just important that we assure adequate vitamin D status for ourselves. It may be even more important that we assure that our kids and grandkids have adequate vitamin D status.

The problem is that in today’s world we are told to slather industrial strength sunscreen on ourselves from head to foot before we leave the house and very few foods in nature provide significant amounts of vitamin D, so most of us rely primarily on vitamin D fortified dairy products and supplements to assure adequate intake of vitamin D. Click here for the latest RDA recommendations for vitamin D intake.

Some people do appear to need greater than RDA levels of vitamin D because they don’t metabolize vitamin D efficiently. They can have adequate intake of vitamin D, but their blood levels of 25-hydroxy vitamin D are low. I recommend that you ask your doctor to check your 25-hydroxy vitamin D levels at your next physical. If they are low, work out a vitamin D supplementation regimen with your doctor to bring your 25-hydroxy vitamin D levels into the optimal range.

 

The Bottom Line

  • A recent study showed that genetic mutations which decrease 25-hydroxy vitamin D levels are associated with a significantly increased risk of developing MS. Based on the relationship of those mutations with 25-hydroxy vitamin D levels, the investigators calculated that every 50% increase in 25-hydroxy vitamin D levels was associated with a 50% decreased risk of developing MS. This study strongly supports the conclusion from previous studies that low vitamin D status significantly increases the risk of developing MS.
  • An earlier Nurses’ Health Study has shown that supplementation with 400 IU/day of vitamin D decreases the risk of developing MS by 40%.
  • The authors of the most recent study concluded “The identification of vitamin D as a causal susceptibility factor for MS may have important public health implications, since vitamin D insufficiency is common, and vitamin D supplementation is both relatively safe and cost effective.” I agree.
  • While MS is a very rare disease, it can be devastating. This alone, is a good enough reason to be sure that you maintain adequate vitamin D status.
  • There is evidence that vitamin D status in our childhood years may be more important than our vitamin D status in later years for determining our risk of developing MS. It is, therefore, not just important that we assure adequate vitamin D status for ourselves. It may be even more important that we assure that our kids and grandkids have adequate vitamin D status.
  • While these and other studies demonstrate the health benefits of maintaining adequate vitamin D status, many Americans don’t do a good job of it. Government surveys show that 40% of Americans are deficient in vitamin D. That’s because we are continually being advised to slather on industrial strength sunscreen before we leave the house, and most naturally occurring foods are relatively poor sources of vitamin D.
  • While the evidence that vitamin D supplementation is effective for preventing MS is strong, evidence that vitamin D supplementation can slow the progression of MS is inconclusive at present. More and better studies are needed before we will have a definitive answer to this question.

 

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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Should We Use Supplements For Cardiovascular Health?

Posted July 10, 2018 by Dr. Steve Chaney

Are You Just Wasting Your Money On Supplements?

Author: Dr. Stephen Chaney

 

supplements for cardiovascular health wast moneyYou’ve seen the headlines. “Recent Study Finds Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.”  You are being told that supplements are of no benefit to you. They are a waste of money. You should follow a healthy diet instead. Is all of this true?

If I were like most bloggers, I would give you a simple yes or no answer that would be only partially correct. Instead, I am going to put the study behind these headlines into perspective. I am going to give you a deeper understanding of supplementation, so you can make better choices for your health.

 Should we use supplements for cardiovascular health?

In today’s article I will give you a brief overview of the subject. Here are the topics I will cover today:

  • Is this fake news?
  • Did the study ask the right questions?
  • Is this a question of “Garbage In – Garbage Out?
  • Reducing Heart Disease Risk. What you need to know.

All these topics are covered in much more detail (with references) in my book “Slaying The Supplement Myths”, which will be published this fall.

 

How Was This Study Done?

supplements for cardiovascular healthThis study (D.J.A. Jenkins et al, Journal of the American College Of Cardiology, 71: 2540-2584, 2018 ) was a meta-analysis. Simply put, that means the authors combined the results of many previous studies into a single database to increase the statistical power of their conclusions. This study included 127 randomized control trials published between 2012 and December 2017. These were all studies that included supplementation and looked at cardiovascular end points, cancer end points or overall mortality.

Before looking at the results, it is instructive to look at the strengths and weaknesses of the study. Rather than giving you my interpretation, let me summarize what the authors said about strengths and weaknesses of their own study.

The strengths are obvious. Randomized control trials are considered the gold standard of evidence-based medicine, but they have their weaknesses. Here is what the authors said about the limitations of their study:

  • “Randomized control trials are of shorter duration, whereas longer duration studies might be required to fully capture chronic disease risk.”
  • “Dose-response data were not usually available [from the randomized control studies included in their analysis]. However, larger studies would allow the effect of dose to be assessed.”

There are some other limitations of this study, which I will point out below.

Is This Fake News?

supplements for cardiovascular health fake newsWhen I talk about “fake news” I am referring to the headlines, not to the study behind the headlines. The headlines were definitive: “Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.” However, when you read the study the reality is quite different:

  • In contrast to the negative headlines, the study reported:
    • Folic acid supplementation decreased stroke risk by 20% and overall heart disease risk by 17%.
    • B complex supplements containing folic acid, B6, and B12 decreased stroke risk by 10%.
    • That’s a big deal, but somehow the headlines forgot to mention it.
  • The supplements that had no significant effect on heart disease risk (multivitamins, vitamin D, calcium, and vitamin C) were ones that would not be expected to lower heart disease risk. There was little evidence from previous studies of decreased risk. Furthermore, there is no plausible mechanism for supposing they might decrease heart disease risk.
  • The study did not include vitamin E or omega-3 supplements, which are the ones most likely to prove effective in decreasing heart disease risk when the studies are done properly (see below).

Did The Study Ask The Right Question?

Most of the studies included in this meta-analysis were asking whether a supplement decreased heart disease risk or mortality for everyone. Simply put, the studies started with a group of generally healthy Americans and asked whether supplementation had a significant effect on disease risk for everyone in that population.

That is the wrong question. We should not expect supplementation to benefit everyone equally. Instead, we should be asking who is most likely to benefit from supplementation and design our clinical studies to test whether those people benefit from supplementation.

supplements for cardiovascular health diagramI have created the graphic on the right as a guide to help answer the question of “Who is most likely to benefit from supplementation?”. Let me summarize each of the points using folic acid as the example.

 

Poor Diet: It only makes sense that those people who are deficient in folate from foods are the most likely to benefit from folic acid supplementation. Think about it for a minute. Would you really expect people who are already getting plenty of folate from their diet to obtain additional benefits from folic acid supplementation?

The NIH estimates that around 20% of US women of childbearing age are deficient in folic acid. For other segments of our population, dietary folate insufficiency ranges from 5-10%. Yet, most studies of folic acid supplementation lump everyone together – even though 80-95% of the US population is already getting enough folate through foods, food fortification, and supplementation. It is no wonder most studies fail to find a beneficial effect of folic acid supplementation.

The authors of the meta-analysis I discussed above said that the beneficial effects of folic acid they saw might have been influenced by a very large Chinese study, because a much higher percentage of Chinese are deficient in folic acid. They went on to say that the Chinese study needed to be repeated in this country.

In fact, the US study has already been done. A large study called “The Heart Outcomes Prevention Evaluation (HOPE)” study reported that folic acid supplementation did not reduce heart disease risk in the whole population. However, when the study focused on the subgroup of subjects who were folate-deficient at the beginning of the study, folic acid supplementation significantly decreased their risk of heart attack and cardiovascular death.  This would seem to suggest using supplements for cardiovascular health is a good idea.

Increased Need: There are many factors that increase the need for certain nutrients. However, for the sake of simplicity, let’s only focus on medications. Medications that interfere with folic acid metabolism include anticonvulsants, metformin (used to treat diabetes), methotrexate and sulfasalazine (used to treat severe inflammation), birth control pills, and some diuretics. Use of these medications is not a concern when the diet is adequate. However, when you combine medication use with a folate-deficient diet, health risks are increased and supplementation with folic acid is more likely to be beneficial.

Genetic Predisposition: The best known genetic defect affecting folic acid metabolism is MTHFR. MTHFR deficiency does not mean you have a specific need for methylfolate. However, it does increase your need for folic acid. Again, this is not a concern when the diet is adequate. However, when you combine MTHFR deficiency with a folate-deficient diet, health risks are increased and supplementation with folic acid is more likely to be beneficial. I cover this topic in great detail in my upcoming book, “Slaying The Supplement Myths”. In the meantime, you might wish to view my video, “The Truth About Methyl Folate.”

Diseases: An underlying disease or predisposition to disease often increases the need for one or more nutrients that help reduce disease risk. The best examples of this are two major studies on the effect of vitamin E on heart disease risk in women. Both studies found no effect of vitamin E on heart disease risk in the whole population. However, one study reported that vitamin E reduced heart disease risk in the subgroup of women who were post-menopausal (when the risk of heart disease skyrockets). The other study found that vitamin E reduced heart attack risk in the subgroup of women who had pre-existing heart disease at the beginning of the study.

Finally, if you look at the diagram closely, you will notice a red circle in the middle. When two or three of these factors overlap, that is the “sweet spot” where supplementation is almost certain to make a difference and it may be a good idea to use supplements for cardiovascular health.

Is This A Question Of “Garbage In, Garbage Out”?

supplements for cardiovascular health garbage in outUnfortunately, most clinical studies focus on the “Does everyone benefit from supplementation question?” rather than the “Who benefits from supplementation?” question.

In addition, most clinical studies of supplementation are based on the drug model. They are studying supplementation with a single vitamin or mineral, as if it were a drug. That’s unfortunate, because vitamins and minerals work together synergistically. What we need are more studies of holistic supplementation approaches.

Until these two things change, most supplement studies are doomed to failure. They are doomed to give negative results. In addition, meta-analyses based on these faulty supplement studies will fall victim to what computer programmers refer to as “Garbage In, Garbage Out”. If the data going into the analysis is faulty, the data coming out of the study will be equally faulty. It won’t be worth the paper it is written on. If you are looking for personal guidance on supplementation, this study falls into that category.

 

Should We Use Supplements For Cardiovascular Health?

 

If you want to know whether supplements decrease heart disease risk for everyone, this meta-analysis is clear. Folic acid may decrease the risk of stroke and heart disease. A B complex supplement may decrease the risk of stroke. All the other supplements they included in their analysis did not decrease heart disease risk, but the analysis did not include vitamin E and/or omega-3s.

However, if you want to know whether supplements decrease heart disease risk for you, this study provides no guidance. It did not ask the right questions.

I would be remiss, however, if I failed to point out that we know healthy diets can decrease heart disease risk. In the words of the authors: “The recent science-based report of the U.S. Dietary Guidelines Advisory Committee, also concerned with [heart disease] risk reduction, recommended 3 dietary patterns: 1) a healthy American diet low in saturated fat, trans fat, and meat, but high in fruits and vegetables; 2) a Mediterranean diet; and 3) a vegetarian diet. These diets, with their accompanying recommendations, continue the move towards more plant-based diets…” I cover the effect of diet on heart disease risk in detail in my book, “Slaying The Food Myths”.

 

The Bottom Line

 

You have probably seen the recent headlines proclaiming: “Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.” The study behind the headlines was a meta-analysis of 127 randomized control trials looking at the effect of supplementation on heart disease risk and mortality.

  • The headlines qualify as “fake news” because:
    • The study found that folic acid decreased stroke and heart disease risk, and B vitamins decreased stroke risk. Somehow the headlines forgot to mention that.
    • The study found that multivitamins, vitamin D, calcium, and vitamin C had no effect on heart disease risk. These are nutrients that were unlikely to decrease heart disease risk to begin with.
    • The study did not include vitamin E and omega-3s. These are nutrients that are likely to decrease heart disease risk when the studies are done properly.
  • The authors of the study stated that a major weakness of their study was that that randomized control studies included in their analysis were short term, whereas longer duration studies might be required to fully capture chronic disease risk.
  • The study behind the headlines is of little use for you as an individual because it asked the wrong question.
  • Most clinical studies focus on the “Does everyone benefit from supplementation question?” That is the wrong question. Instead we need more clinical studies focused on the “Who benefits from supplementation?” question. I discuss that question in more detail in the article above.
  • In addition, most clinical studies of supplementation are based on the drug model. They are studying supplementation with a single vitamin or mineral, as if it were a drug. That’s unfortunate, because vitamins and minerals work together synergistically. What we need are more studies of holistic supplementation approaches.
  • Until these two things change, most supplement studies are doomed to failure. They are doomed to give negative results. In addition, meta-analyses based on these faulty supplement studies will fall victim to what computer programmers refer to as “Garbage In, Garbage Out”. If the data going into the analysis is faulty, the data coming out of the study will be equally faulty. It won’t be worth the paper it is written on. If you are looking for personal guidance on supplementation, this study falls into that category.
  • If you want to know whether supplements decrease heart disease risk for everyone, this study is clear. Folic acid may decrease the risk of stroke and heart disease. A B-complex supplement may decrease the risk of stroke. All the other supplements they included in their analysis did not decrease heart disease risk, but they did not include vitamin E and/or omega-3s in their analysis.
  • If you want to know whether supplements decrease heart disease risk for you, this study provides no guidance. It did not ask the right questions.
  • However, we do know that healthy, plant-based diets can decrease heart disease risk. I cover heart healthy diets in detail in my book, “Slaying The Food Myths.”

 

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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