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Dr. Cannell on vitamin D for the treatment of depression

Posted on: January 15, 2015   by  John Cannell, MD


Sometimes we miss an important paper. This was the case with Professor Simon Spedding’s 2014 meta-analysis of randomized controlled trials (RCT) that used vitamin D to treat depression; Professor Spedding is at the University of South Australia.

Depression is a terrible disease. To a person suffering from depression, sometimes it seems like life is not worth living. It is the leading cause of disability in the U.S. As a psychiatrist, I can tell you that many times conventional antidepressants do not work and patients are left hanging in “partial remission,” which means their depression has improved but is still present.

There is a controversy raging within the academic field of psychiatry; some are claiming that certain RCTs used by pharmaceutical companies to get FDA approval of antidepressants were flawed and that antidepressants are no better than placebo when it comes to treating depression.

In his analysis of the effects of vitamin D supplementation on depression, Dr. Spedding excluded RCTs that had “biological flaws.” Professor Robert Heaney first described the concept of biological flaws in studies of nutrients. In Dr. Spedding’s review, biologically flawed scientific studies included RCTs with one of the following:

  1.  Inappropriate interventions (interventions that did not include vitamin D).
  2.  Interventions producing the opposite effect of that intended (interventions that included Vitamin D, but reduced the 25OHD level in the intervention group).
  3.  Ineffective interventions that did not improve vitamin D status (did not significantly change the 25OHD level).
  4.  Where the baseline 25OHD level was not measured in the majority of participants.
  5.  Where the baseline 25OHD level indicated sufficiency (not deficiency) at baseline.

I’d like to add one more criterion which well-designed RCTs should uphold: the RCT must include subjects with the condition being studied. For example, researchers should not conduct a RCT of vitamin D in non-depressed subjects to see if vitamin D has a treatment effect on depression or overall mood.

Dr. Spedding found that 8 of the 15 extant RCTs had biological flaws. Of the 7 RCTs without flaws, 6 RCTs found that vitamin D significantly improved depression.

Dr. Spedding concluded:

“The effect size for Vitamin D in depression demonstrated in this meta-analysis is comparable with the effect of anti-depressant medication, an accepted treatment for depression. Should these results be verified by future research, these findings may have important clinical and public health implications.”

I treat a lot of patients with major depression. When I begin treatment, I place them all on 50,000 IU/day of vitamin D3 for two weeks and then place them on a maintenance dose of 10,000 IU/day. I wish I could tell you that vitamin D is a panacea for depression; it is not. It certainly helps some patients but most patients require treatment with conventional medication as well, and even then, some of those do not achieve full remission of their depression.


Spedding S.Vitamin D and depression: a systematic review and meta-analysis comparing studies with and without biological flaws. Nutrients. 2014 Apr 11;6(4):1501-18. doi: 10.3390/nu6041501. Review.

4 Responses to Dr. Cannell on vitamin D for the treatment of depression

  1. Rita Celone Umile

    I wonder if sunshine would provide relief from depression for reasons in addition to vitamin D. I wonder if in lieu of sunshine perhaps light therapy plus vitamin D supplementation might provide relief from depression.

  2. IAW

    Hi Rita!
    When this blog first came out, I was going to ask Dr. Cannell what blood level range this then left these people with? Obviously they have 50ng/ml or above but just how high are they?
    You making the above statement is also prompting the following.
    Dr. Cannell when you treat anyone for depression I would assume that you also check to see if they have a thyroid problem, meaning hypothyroidism since it causes depression. I would like to know what criteria and tests you use to determine that they either do or do not have hypothyroidism?
    Since I am hypothyroid, I have read many books and websites by both doctors and patients. The absolute consensus is that using just a TSH test to determine thyroid status does not work and just using T4 to treat is not optimal. They promote using Free T4 and Free T3 tests to determine status and using only the upper third of those ranges because those lab ranges are inadequate. The best summary I have ever seen (and just found a week ago) comes from Dr. Henry Lindner. If you click on http://hormonerestoration.com/Thyroid.html it will come to “Thyroid Hormone: T3” an excellent read! If you then scroll to the bottom and click on “Draft of academic paper on the appropriateness of relying on the TSH test to diagnose and treat hypothyroidism” is another excellent read. IT IS THE BEST SUMMARY OF THE ISSUE/PROBLEM I HAVE EVER READ!
    Since Hashimoto’s disease causes hypothyroidism and it is an autoimmune disease, obviously a Vitamin D deficiency plays into some cases of hypothyroidism. Other testing doctors do not even bother to do is thyroid antibody testing.
    As a side note, I also just found out last week that unless my mother’s TSH level is “out of range” Medicare will not pay for any further tests! If the following was put into practice today, my Mom could be diagnosed with hypothyroidism. “Recent laboratory guidelines from the National Academy of Clinical Biochemistry indicate that more than 95% of normal individuals have TSH levels below 2.5 mU/liter”.

  3. Rebecca Oshiro

    Thank you very much for the link, IAW, I have squirreled it away for future reading. Very informative.

  4. [email protected]

    I agree that supplementation can be helpful, but, to echo Dr. Cannell (I am a big fan of his) it is not the panacea. I began educating myself in order to help several families members that are challenged with depression. What I have found is that a combination of a good therapist, healthy lifestyle (includes some supplementation, exercise and eating healthy) and exposure to sunlight seems to be the best treatment to this challenging ailment. With two family members, I am seeing dramatic change in their lives when they are disciplined to involve the prior mention aspects. I am guessing sunlight is helping because at high level there are two main things happening: An immune response and production of D or Calcitriol. Along with D (Calcitriol), sunlight helps produce things like beta endorphins, melanocyte stimulating hormone, ACTH, NSP, and CGRP. It is my belief that all of these things work in conjunction with D to help balance humans systemic health. I am not a DR. and I am not qualified to give advice. I am a believer in D, grateful for D Council’s work and have learned quite a bit in order to help some people I love very much.

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