Clinical Trials of vitamin D can have “biological flaws” – Jan 2015

Vitamin D for treatment of depression Vitamin D Council

Dr. Cannell references two studies on VitaminDWiki

Anti-depression medication about as good as big increase in vitamin D – meta-analysis of flawless data April 2014
Why randomized controlled trials of calcium and vitamin D sometimes fail – June 2012

Dr. Cannell summarizes the biological flaws as

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.
6. RCT must include subjects with the condition being studied (i.e. Depression)

VitaminDWiki would add the following flaw
Study ignored the benefits to subset of participants with vitamin D levels which got > 40 ng

Summary by Dr. Cannell on Vitamin D and depression

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.

Summary of Depression and Vitamin D Vitamin D Council updated 2012

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See also VitaminDWiki

• All items in category Depression and Vitamin D 268 items
• All items in category Meta-analysis and Vitamin D 667 items
• Depression and low Vitamin D – review 2014
• Slight depression not reduced by adding vitamin D if already had enough (no surprise) – meta-analysis – Nov 2014
• Just 1500 IU of Vitamin D significantly helps Prozac – RCT March 2013
• Depression might be reduced by vitamin D – meta-analysis March 2014
• Reasons for low response to vitamin D
  many reasons why vitamin D monotherapy may not result in benefits in an individual
• Vitamin D intervention -100 active clinical trials as of May 2018