Are vitamin D supplements causing more ill than good?

TAKING vitamin D supplements has little impact on health, according to a new review of trial evidence.

Researchers concluded that the capsules did not reduce the risk of heart attacks, strokes, cancers or bone fractures in the general population by more than 15 per cent.

Previous studies have shown a strong link between vitamin D deficiency and poor health and early death. But newer evidence suggests the association is chiefly due to low vitamin D being the result, not the cause, of ill health, it is claimed.

In the latest study based on 40 randomised trials, researchers concluded that the effects of vitamin D supplementation on heart attack, stroke, cancer and bone fracture risk lay below a ‘futility threshold’ - meaning further investigation would probably be pointless.

For hip fracture, some trials even suggested an increased risk from vitamin D supplements.

The scientists, led by Dr Mark Bolland from the University of Auckland in New Zealand, wrote in the medical journal The Lancet Diabetes and Endocrinology: ‘There is little justification for prescribing vitamin D supplements to prevent myocardial infarction (heart attack) or ischaemic heart disease, stroke or cerebrovascular disease, cancer, or fractures, or to reduce the risk of death.

Professor Karl Michaelsson pointed out in the journal: ‘Without stringent indications... there is a legitimate fear that vitamin D supplementation might actually cause net harm.’