This latest episode of the Barbell Medicine Podcast features Dr. Austin Baraki sharing his current understanding about the accumulated research on the relationships between vitamin D and health and the value (or not) of vitamin D supplementation. And if I were to summarize his main point, it is that reduced vitamin D is associated with many diseases states, but there’s little data suggesting that increasing vitamin D improves those disease states. Basically, it’s a practical lesson in the old Stats 101 chestnut “correlation does not necessarily mean causation.”
Throughout the conversation, Dr. Baraki talks about the research and the limits of the research which fails to show that healthy people have significantly better outcomes for supplementing with vitamin D. He also says that unless there is a disease state that reduces vitamin D absorption or availability in the body, supplementation does not seem to improve health outcomes.
Many times in these conversations with experts there’s advice to us lay-folk on how to interpret data, and I think that’s not really a reasonable expectation. I read, listen and think about this stuff all the time for fun, and I’m not reading studies. I don’t feel qualified. Instead, I seek information from the best interpreters of data out there that I can find and put my trust them to do their jobs. Over time, I have gotten better at learning who to trust. But as they point out, ten years ago the general consensus was that most people have insufficient vitamin D and would benefit from supplementation. But I don’t think it’s reasonable to expect an everyday human to keep up as that recommendation has evolved in the last decade.
Unfortunately, my experience of medical doctors suggests it may not be reasonable to expect all of them to keep up on such details, either. The same doctor who suggested I cut out carbs to treat my autoimmune diseases also ordered all sorts of tests, including vitamin D. I questioned her about all the tests at the time–are these appropriate and necessary for the condition I was there to have treated? I was generally aware that we have a culture of increased, potentially unnecessary screening, but I didn’t have a particular reason to question the vitamin D test except that I already supplemented with vitamin D. And now, in this podcast, I hear another reason, as Dr. Baraki said that many autoimmune diseases are associated with decreased amounts of vitamin D, and I have multiple autoimmune conditions. It sounds like it is reasonable to expect that my vitamin D levels may be lower sometimes, but there’s little reason to assume supplementation would improve my conditions.
So now what? My pill box right now includes a daily dose of 2000 IU(1) of vitamin D. I began taking it because I live in a state with one of the greyest skies in the US (although climate change may be changing our status), and I’m certain I don’t get either enough daily sunlight nor enough fatty fish or supplemented dairy to get the recommended amount. However, I acknowledge it’s a “reassurance” supplement for me. There’s no evidence it’s making anything better, although I feel that way about nearly all supplementation! My other daily supplements include chaste tree/vitex (an ancient remedy for “female problems” that has decreased my PMS-related migraine symptoms) and creatine monohydrate. I also take 4-6 medications a day. The day to day evidence that these are doing what I want them to do can be pretty slim. And when we add in the known confounders of anecdotal data like the placebo effect, I’m somewhat having to take it on faith.
And I feel like that’s what each of us are likely doing when we take on a preventative supplement like vitamin D. Of course, science is a great tool for helping us weed through the anecdata and to give it context. I’m open to the possibility that I could stop taking vitamin D and have no ill effects. I will keep my ear open for further conversations on the topic, and in time, maybe I won’t replace the bottle when I run out.
Do you supplement with vitamin D? How do you decide which preventative supplements to take and which aren’t worth the bother? I’d love to hear from you! Please leave a comment below or find and follow the conversation over at Progressive Strength on Facebook!
(1) I will happily acknowledge that this amount is excessive. If I recall correctly, I was looking to purchase 1000IU last time I was low, and they were out of stock, so I bought the next-smallest amount. I don’t believe there’s much risk of toxicity at this amount, especially since I don’t live off of fatty fish and egg yolks, but next time around, I will look for a smaller dosage.
Progressive Strength 
thank you for those reflections; to your ‘research and then trust… I can only add: I call it educating my intuition. And then trust. Get grounded. I am taking Vit D 4000iU (I seem to remember a GP once said to me even at that amount there was no toxicity. I started it last yr again to improve my chances with covid (together with 1g Vit C). – I am not vaccinated because I tested pos. for allergies to a series of emulsifiers such as PEG in the past. And I live in Britain. – I understand and appreciate the distinction between causation and correlation. However, my thinking is that most GPs are heavily biased on the side of evidence that comes from Big Pharma, And Big Pharma will say on Vits ‘there is no evidence…’ – because THEY are not testing for it – because they can’t expect any profit. So if I can supplement at low cost and reasonable expectation of some pos correlation…, then I think that is a reasonable course of action. As a social worker, I used to explain that comment from medics (‘no evidence’) to my clients with gesture of wearing blindfold and blinkers while repeating ‘there is no evidence…’ They all got it. 🙂
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Unfortunately, it sounds to me that you and I are not in agreement. The point I was trying to make in my post was the very lack of trust you seem to be expressing–if I am understanding you correctly, you don’t trust professionals because some of them can be influenced by the marketing of pharmaceutical companies. Whereas, I think we need to be able to trust our professionals, and a few taking advantage of their positions of privilege unfortunately make it harder for us to discern who to trust. I absolutely do not agree with your decision to not get vaccinated.
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your last sentence aside, I don’t see much in terms of disagreement, only nuances. Perhaps we have different cultural experiences – I don’t see GPs in the UK ‘taking advantage of privilege’ as much as being demoralised and absent from critical thinking, most of them. That makes it difficult to discern who to trust as you say. There is absolutely no need or right for you to disagree with my decision , not on the basis of the information you have in any case. Best wishes,
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The purpose of science and the scientific process is to look for patterns in data that we may miss due to our personal biases. Our intuitions are often wrong as the human mind is prone to many fallacies when our personal beliefs are challenged. Putting our own feelings ahead of the science is choosing willful ignorance, and quite frankly, selfish. I am immunocompromised and vaccination is a public health responsibility, not a matter of personal choice. The science is overwhelming and conclusive. My judgment of your decision is based upon your stated reasoning–that you made the decision based upon your intuition and a distrust in medical professionals. I appreciate your comments, and I don’t mind having the dialogue, and it is important to me that my meaning and intent be clearly understood on this blog. I do not want my arguments to be misconstrued. Take care.
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it seems you are jumping to value judgment instead of taking in the facts here. As long as I am not putting you at risk or breaking a law my decision is mine and mine alone. That aside it is based on medical assessment as stated. Science when applied in practice never works without critical evaluation and weighing up of values. You seen to have ignored that and jumped straight to some views you disagreed with.
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“As long as I’m am not putting you at risk.” Like being a carrier for a disease that can kill me when there’s a safe, effective way for you to not be a carrier? I called it a selfish choice, and that is value judgment, and I will own it. I say it is selfish to say “my choices are my own” when your choices directly impact the health and safety of other people.
However, research says debating this with you will not change your mind. That people who think in conspiratorial ways only dig further into their beliefs when pushed. So, this will be my last reply. I wish you well, and I hope your decisions do not hurt people around you.
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