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A look back at 2012: a few key randomized controlled trials

Posted on: December 31, 2012   by  Brant Cebulla

A look back at 2012: a few key randomized controlled trials


Researchers and policy makers are waiting for more randomized controlled trials to come out before they improve recommendations for vitamin D intake requirements. Randomized controlled trials are considered the “gold standard” of research because they can very strictly discern if an intervention (like vitamin D) has a causative effect versus just an association. And if there is an effect, what is the effect? Positive? Negative?

This past year, there were quite a few randomized controlled trials using vitamin D. The list below is by no means a comprehensive list, but lists quite a few randomized controlled trials that were published in 2012. These here are RCTs that either (a) the Vitamin D Council already covered, (b) received quite a bit media coverage or (c) popped up in a PubMed search of “vitamin D,” with the filter of “randomized controlled trial.”

I omitted including several RCTs that just looked at “markers” of disease. Of these, quite a few looked at vitamin D’s effect on markers of diabetes or markers of cardiovascular disease; both of which vitamin D shows a repeated mixed effect on markers of these diseases. Longer RCTs underway will be able to look at the effect of vitamin D on these diseases beyond just markers.

So, here they are. Thanks for all your support this 2012, and we look forward to seeing more trials in 2013.

Cardiovascular Health

  • In a UK study, 305 adults were randomized to take either 400 or 1,000 IU/day for one year to see if there was any effect on cardiovascular risk factors. They found no effect. The low dosage leaves more study to be desired.

Wood AD et al. Vitamin D3 supplementation has no effect on conventional cardiovascular risk factors: a parallel-group, double-blind, placebo-controlled RCT. J Clin Endocrinol Metab, 2012.

  • In a study out of Egypt, Dr Shedeed administered 1,000 IU of vitamin D/day or placebo to 80 infants with heart failure for 12 weeks. At the end of the trial, Dr Shedeed observed a significant improvement of heart failure score, left-ventricular end-diastolic diameter, left-ventricular end-systolic diameter and ejection fraction.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/02/28/infant-heart-failure-and-vitamin-d-supplementation/

  • Researchers administered 50,000 IU/week for 8 weeks or placebo on 151 adults to see if vitamin D had any effect on cholesterol. In 8 week’s time, vitamin D did not have an effect.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/10/08/rct-shows-curious-relationship-between-d-and-cholesterol/


  • Researchers wanted to know if vitamin D could reduce the occurrence of exacerbations in patients with chronic obstructive pulmonary disease. They  found that only patients that started with levels less than 10 ng/ml saw a reduction in exacerbations after dosing with 100,000 IU of vitamin D once per month or placebo. Although the researchers were disappointed with the results, this study is a good reminder that it’s important to screen levels in COPD patients and make sure they do not have severe deficiency.

Read Jim Larsen’s blog on the study here: http://blog.vitamindcouncil.org/2012/02/18/high-doses-of-vitamin-d-to-reduce-exacerbations-in-copd-a-closer-look/

Cystic Fibrosis

  • In a trial of only 30 patients, a one-time dose of 250,000 IU of vitamin D in patients with cystic fibrosis decreased the need for antibiotics, the need to visit the hospital and reduced mortality risk five-fold.

Read our full blog on the study here: http://blog.vitamindcouncil.org/2012/05/03/rct-shows-vitamin-d-may-benefit-patients-with-cystic-fibrosis/


  • In a study out of Iran, researchers wanted to know if vitamin D combined with Prozac could work better than just Prozac alone in treating depression. They administered 1,500 IU/day. After four weeks, they found a significant improvement in the vitamin D plus Prozac group compared to just Prozac alone.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/11/06/rct-vitamin-d-and-prozac/

  • In another study that administered vitamin D by itself at 40,000 IU/week for 6 months, vitamin D was no better than placebo in reducing depressive symptoms. An important distinction here is to note that these patients were not necessarily depressed at baseline or at any point during the study.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/07/20/can-vitamin-d-supplementation-help-relieve-the-symptoms-of-depression/

General Pain and Well-Being

  • Researchers wanted to see if vitamin D could ease pain symptoms in patients with sickle cell disease. They administered 4,000 to 100,000 IU of vitamin D once per week or placebo. They found patients who received vitamin D experienced less “pain days” and improved general well-being.

Osunkwo I et al. High dose vitamin D therapy for chronic pain in children and adolescents with sickle cell disease: results of a randomized double blind pilot study. Br J Haematol, 2012.

  • Researchers out of Italy wanted to know if vitamin D could reduce musculoskeletal pain in patients taking bisphosphonates. They administered a onetime dose of 300,000 IU and then the patients were clinically evaluated for pain after 7 days. Vitamin D indeed reduced pain.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/09/24/fosamax-jaw-part-1-d-reduces-inflammation-and-pain-after-osteoporosis-treatment/

  • Researchers wanted to know if vitamin D could improve symptoms of general muscle pain for non-Western immigrants living in the Netherlands. They administered a onetime dose of 150,000 IU or placebo at baseline and 6 weeks. After 12 weeks, the vitamin D group showed better improvement in ability to walk stairs and reported less pain.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/11/15/rct-vitamin-d-improves-musculoskeletal-pain-in-non-western-immigrants/


  • In a study out of Israel, researchers randomized fifty patients with hepatitis C to take either 2,000 IU of vitamin D/day for 24 weeks in conjunction with traditional therapy or just traditional therapy. They found the vitamin D group had better viral response.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/03/27/rct-shows-benefits-of-vitamin-d-supplementation-among-hepatitis-c-patients/

Lupus (SLE)

  • In a very recent study, vitamin D at 2,000 IU/day reduced flare-ups and antibodies in patients with lupus. They administered this dose for one year in 178 patients.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/12/29/vitamin-d-helps-control-lupus-says-new-randomized-control-trial/

Multiple Sclerosis

  • Researchers wanted to know if vitamin D as an add on therapy to interferon β-1b could reduce disease activity in an MRI scan. They found that 20,000 IU of vitamin D/week reduced activity but did not reduce relapse rate.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/09/08/rct-vitamin-d-supplementation-in-patients-with-ms/

  • Another study out of Norway also administered 20,000 IU/week or placebo for 96 weeks and found no effects on multiple-sclerosis associated outcomes.

Kampman MT et al. Effect of vitamin D3 supplementation on relapses, disease progression, and measures of function in persons with multiple sclerosis: exploratory outcomes from a double-blind randomised controlled trial. Mult Scler., 2012.

Respiratory infections

  • In a study out of New Zealand, 322 participants took 100,000 IU of vitamin D once per month or placebo for 18 months. They found that vitamin D does not help the incidence or severity of respiratory tract infections.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/10/04/a-closer-look-vitamin-d-no-match-for-common-cold/

  • In another study out of Mongolia, researchers randomized 247 children to 300 IU of vitamin D/day in fortified milk or placebo for three winter months. They found that vitamin D reduced the incidence of respiratory infections.

Camargo CA Jr et al. Randomized trial of vitamin D supplementation and risk of acute respiratory infection in Mongolia. Pediatrics, 2012.

  • In yet another study, 4,000 IU of vitamin D per day for one year reduced the incidence of respiratory infections and the need for antibiotics compared to placebo. This study differs from the New Zealand study in that they administered daily doses and the participants had low levels to begin with.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/12/22/new-study-says-vitamin-d-fights-respiratory-infections-reduces-need-for-antibiotics/

Skin Disorders

  • Researchers administered 1,600 IU of vitamin D/day or placebo in 60 patients with atopic dermatitis to see if it could improve the severity of the condition. The vitamin D group did indeed improve the condition while placebo did not.

Amestejani M et al. Vitamin D supplementation in the treatment of atopic dermatitis: a clinical trial study. J Drugs Dermatol, 2012.

  • Researchers out of Brazil wanted to see if vitamin D could help aid the healing of leg ulcers. They administered 50,000 IU of vitamin D/week for two months versus placebo. They found a trend that vitamin D helped reduce the size of leg ulcers.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/12/19/rct-vitamin-d-may-help-heal-leg-ulcers/

Traumatic Brain Injury

  • Patients admitted to the hospital for traumatic brain injury were injected with one mg/kg of progesterone intramuscularly every 12 hours for 5 days and also 200 IU/kg of vitamin D once-a-day for 5 days. For a 150 lb person, this would be 13,600 IU of vitamin D/day for five days. They compared this treatment to placebo or progesterone alone. They found that vitamin D and progesterone improved consciousness best and decreased mortality.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/12/18/rct-vitamin-d-levels-and-traumatic-brain-injury/


  • Researchers wanted to see if vitamin D supplementation could reduce the prevalence of tuberculosis skin test conversion in 120 Mongolian children. They administered 800 IU/day for six months and found a trend toward fewer conversions in the vitamin D group.

Read our blog on the study here: http://blog.vitamindcouncil.org/2012/09/21/rct-vitamin-d-supplementation-and-tb-in-mongolian-children/

2 Responses to A look back at 2012: a few key randomized controlled trials

  1. yinhong

    Thank you, an interesting overview Brant. Hasn’t there been any RCT for any cancers with Vitamin D?

  2. Brant Cebulla

    Good question, yinhong. None that came out this past year. Here’s a recap of what has been done:

    *In 2007, an RCT reported a 77% reduced risk of all-cancer incidence between the first and fourth years of the trial using 1100 IU/day vitamin D3 and 1450 mg/day calcium supplementation.

    *Another RCT in 2009 using 1000 IU/day vitamin D and 1500 mg/day calcium found no effect on cancer incidence for four year follow-up.

    *Another RCT that slowly release findings in 2006, 2009 and 2011 using 400 IU/day vitamin D and 1500 mg/day calcium found a reduced cancer incidence only for those who did not take vitamin D prior to the study.

    The shortcomings of all these studies, however, is that vitamin D and calcium were taken together, so we don’t know if it was vitamin D that was effective, or calcium, or both.

    In 2012, an “open label” trial (where there was no placebo group) found that 4000 IU vitamin D/day bettered the prognosis of low-grade prostate cancer. I think this was probably the most interesting/exciting study to come out of cancer-vitamin D research last /year.

    Trials are underway to see if vitamin D prevents cancer. In these studies, they’re using roughly 2000-3000 IU of vitamin D/day. Results, however, won’t be released until 2017-2020, save maybe a smaller trial that may publish results by 2014-2016.

    Quite a few trials also underway to see if vitamin D can aid in treatment of cancers: http://www.clinicaltrials.gov/ct2/results?term=vitamin+d+and+cancer&Search=Search

    Maybe we’ll see some of these released this year?



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