Vitamin D could reduce the risk of osteoporosis – in unborn babies
Reported October 13, 2008
Giving pregnant women Vitamin D supplements could reduce the risk of their babies developing osteoporosis in later life, according to UK researchers.
Results of the new Arthritis Research Campaign-funded trial, the UK’s first, could have a significant effect on public health policy and lead to the routine supplementation of pregnant women with Vitamin D.
Doctors in Southampton who are running the £650,000 study believe that giving supplements to Vitamin D-deficient pregnant women could increase the bone density of their babies at birth and ensure their bones remain strong and healthy throughout their lives.
“This is the first randomised controlled trial to formally assess the effectiveness of prenatal intervention on the later risk of osteoporosis in the newborn offspring – to look at whether the bone mass of an individual can be modified before it is even born,” explained Dr Nick Harvey, clinical lecturer in rheumatology at the MRC Epidemiology Resource Centre at the University of Southampton, who is running the study with Professor Cyrus Cooper.
Previous research by Professor Cooper’s team showed that children whose mothers were Vitamin D deficient during pregnancy had weaker bones at birth and at the age of nine.
Their research also revealed that a combination of poor bone growth of the foetus in the womb plus diet and exercise during a child’s early life are both important in the development of strong bones and avoiding osteoporosis.
However, according to Dr Harvey, what goes on in the womb may play the more significant role in the development of healthy bones throughout life.
“That period of very early development is potentially the cause of permanent change during the growth trajectory. Calcium intake during childhood can modify growth temporarily but it doesn’t have a long-term effect,” he said. “It may be that what happens during the inter-uterine period can give a lifetime of benefit, so for these mothers – for all mothers – this is a really, really important study.”
One hundred and eighty pregnant women from the Southampton area attending the Princess Anne Hospital will take part in the 18-month pilot study of the trial, which will then be extended to more than 1,000 women recruited from centres in Sheffield and Oxford over a further two and a half years.
Pregnant women will be recruited when they attend their 12-weekly pre-natal scan. Volunteers will be split into three groups, with one group taking 800 iu of Vitamin D, the second group taking 1,000 iu of Vitamin D, and the third group taking a placebo pill for the duration of their pregnancy. Their babies’ bone density will be measured by DXA scan within the first ten days after birth.
The women will also fill in questionnaires looking at what they eat, and how much Vitamin D and calcium they get from their diet. The main trial will test which ever dose of Vitamin D is shown to be more effective in the pilot study, versus placebo.
Vitamin D deficiency is extremely common in pregnancy, affecting up to 18 per cent of white women and a far higher proportion of Asian women, according to recent studies. Despite this, current health advice to pregnant women is inconsistent.
Vitamin D is necessary for the bones to absorb calcium, which plays a key role in the formation of healthy bones. It is found mainly in sunlight and to a lesser extent in oily fish and other foods.