Vitamin D supplements have no significant effect on preventing heart attack,
stroke, cancer or bone
fractures, according to a review of scientific evidence published.
Researchers led by Mark Bolland of the University of Auckland in New Zealand
looked at 40 high-quality trials to see if supplements met a benchmark of
reducing risk of these problems by 15% or more.
Previous research had seen a strong link between vitamin
D deficiency and poor health in these areas.
genes may be a source of Vitamin D deficiency
Not the cause
But the new study, published in The Lancet Diabetes & Endocrinology,
strengthens arguments that vitamin D deficiency is usually the result of ill
health – not the cause of it.
Its authors say there is "little justification" for doctors to
D supplements as a preventive measure for these disorders.
"Available evidence does not lend support to vitamin D supplementation
and it is very unlikely that the results of a future single randomised clinical
trial will materially alter the results from current meta-analyses," they
Vitamin D is a key component for healthy bones, teeth and muscles.
It is produced naturally when the skin is exposed to sunlight or derived
from foods such as oily fish, egg yolks and cheese.
In March last year, British scientists, in a comparison of 4 000 women,
found that vitamin
D supplements taken in pregnancy made no difference to the child's bone
And in September 2012, researchers at New York's Rockefeller University saw
no evidence that vitamin D supplements lowered cholesterol,
a factor in heart disease, at least over the short term.
In contrast, a November 2012 investigation into pregnant women who lived in
high-latitude, northern hemisphere countries with long, dark winters found a
link between low levels of natural vitamin D and an increased risk of multiple
sclerosis (MS) in their offspring.
For these women, taking vitamin D supplements to offset the effects of long
periods without sunlight could be advisable, according to that research.
all vitamin D supplements the same?
evidence that vitamin D is good for bones