New analysis suggests that further trials of vitamin D have little chance of showing health benefits

A new study concludes that evidence is lacking for substantial health benefits of vitamin D—and that results of several multi-million-dollar trials currently underway are unlikely to alter this view.

The study, published in The Lancet Diabetes & Endocrinology, examines existing from 40 randomised controlled trials – the gold standard for proving cause and effect – and concludes that vitamin D supplementation does not prevent heart attack, stroke, cancer, or bone fractures in the general population by more than 15%. Thus, vitamin D , which are taken by nearly half of US adults, probably provide little, if any, health benefit.

Previous observational studies have shown that vitamin D deficiency is strongly associated with poor health and early death. However, evidence from now indicates that this association is not causal – that is, that supplementation is not likely to have any benefit. In line with this idea, the results of a large systematic review by Philippe Autier and colleagues, published in December 2013, also in The Lancet Diabetes & Endocrinology, suggested that low levels of vitamin D are a consequence, not a cause, of ill health.

In the new study, Dr Mark Bolland of the University of Auckland, New Zealand, and colleagues build on this evidence using several types of meta-analysis, including a 'futility analysis', which predicts the potential of future study results to sway existing evidence. The results of their study indicate that the effect of vitamin D, taken with or without calcium, on heart attack, stroke, cancer, and total fracture lies below a 'futility threshold'. For hip fracture, the results of some trials even suggested increased risk with vitamin D supplementation. The authors' analysis of whether vitamin D supplementation can reduce mortality by 5% or more was inconclusive.

Writing in a linked Comment, Professor Karl Michaëlsson, of Uppsala University in Sweden, concludes that, "Without stringent indications—i.e. supplementing those without true vitamin D insufficiency—there is a legitimate fear that vitamin D supplementation might actually cause net harm."

More information: www.thelancet.com/journals/lan… (13)70212-2/abstract

add to favorites email to friend print save as pdf

Related Stories

USPSTF: Vitamin D, calcium supplements don't prevent fx

Feb 26, 2013

(HealthDay)—For non-institutionalized postmenopausal women, the U.S. Preventive Services Task Force (USPSTF) recommends against daily supplementation with ≤400 IU of vitamin D3 and ≤1,000 mg of calcium for primary prevention of fractures, and a lack of e ...

Can vitamin B supplements help stave off stroke?

Sep 18, 2013

New evidence suggests that taking vitamin B supplements may help reduce the risk of stroke. The research appears in the September 18, 2013, online issue of Neurology®, the medical journal of the American Academy of Neurol ...

Who benefits from vitamin D?

Aug 13, 2013

Studying the expression of genes that are dependent on vitamin D makes it possible to identify individuals who will benefit from vitamin D supplementation, shows a University of Eastern Finland study published recently in ...

Recommended for you

Patient-centered medical homes reduce costs

2 hours ago

The patient-centered medical home (PCMH), introduced in 2007, is a model of health care that emphasizes personal relationships, team delivery of care, coordination across specialties and care settings, quality ...

New mums still excessively sleepy after four months

3 hours ago

(Medical Xpress)—New mums are being urged to be cautious about returning to work too quickly, after a QUT study found one in two were still excessively sleepy four months after giving birth.

It's time to address the health of men around the world

3 hours ago

All over the world, men die younger than women and do worse on a host of health indicators, yet policy makers rarely focus on this "men's health gap" or adopt programs aimed at addressing it, according to an international ...

User comments