Previous studies have suggested that vitamin D supplementation offers certain health benefits. However, new research published in the journal The Lancet Diabetes & Endocrinology suggests that current evidence fails to support the claims of the health benefits of vitamin D supplements and that future studies will unlikely reveal supporting evidence.
In other words, there is little evidence that vitamin D supplementation yield certain health benefits.
Vitamin D is a fat-soluble nutrient that enhances the intestinal absorption of calcium and phosphate. Nicknamed the “sunshine vitamin,” vitamin D is available through food sources such as spinach, kale, okra, collards, soy beans, white beans, and some fish such as sardines, salmon, perch, and rainbow trout. The body also synthesizes the vitamin after adequate exposure to sunlight.
For individuals who did not receive adequate levels of sunlight, vitamin D supplementation has been touted as a way to prevent disease and ill health associate with low levels of the vitamin.
Unfortunately, the present study suggests that vitamin D supplements do not offer the health benefits previously claimed. In fact, the researchers state that their most recent analysis of the data from previous studies suggests that many of the associations between vitamin D and improved health are not causal.
To investigate the health benefit claims of vitamin D supplementation, researchers led by Dr. Mark Bolland of the University of Auckland in New Zealand assessed 40 randomized controlled trials that analyzed the use of vitamin D supplements, with or without calcium supplements.
In regards to reduced mortality, the link to vitamin D was inconclusive.
The researchers, however, conclude that previous studies indicate that vitamin D supplementation is unlikely to reduce the incidence of heart attack, heart disease, stroke, cancer, and bone fractures.
Dr. Bolland comments on the findings to Medical News Today:
“Lots of observational studies that measure vitamin D levels at baseline and compare health outcomes over time between groups with high levels and low levels have reported associations between low vitamin D levels and poor health outcomes. These studies are not able to determine causality because of their design. It is possible that low vitamin D levels are simply a marker of ill health, rather than having a causal relationship.”
The researchers do caution that additional studies need to be performed on vitamin D supplementation in individuals with vitamin D deficiencies:
“Trials of vitamin D supplementation in individuals with more pronounced vitamin D deficiency might produce different result. However, before such trials are undertaken, there should be strong evidential support underpinning the trial rationale, particularly in view of the absence of effects seen in studies done thus far.”
Dr. Bollard additionally does not encourage individuals to reduce their intake of vitamin D, “The main message is that if you are otherwise healthy and active, you are likely to receive enough sunshine to have adequate vitamin D levels and don’t need to take vitamin D supplements.”
Another recent study from researchers at the International Prevention Research Institute in Lyon, France has also cast doubt on the purported benefits of vitamin D supplementation.
Individuals concerned about vitamin D levels should consider getting enough sunlight rather than using supplements as naturally synthesized levels appear more beneficial than supplementation.
Doubts cast over benefits of vitamin D supplements: http://www.medicalnewstoday.com/articles/269768.php
The effect of vitamin D supplementation on skeletal, vascular, or cancer outcomes: a trial sequential meta-analysis: http://www.thelancet.com/journals/landia/article/PIIS2213-8587(13)70212-2/abstract
Study questions health benefits of vitamin D supplementation: http://www.medicalnewstoday.com/articles/271589.php
Calcium Supplements with Vitamin D: https://commons.wikimedia.org/wiki/File:500_mg_calcium_supplements_with_vitamin_D.jpg