Touching Lives - October 2012
Shedding light on vitamin D deficiency
In the last year Action Medical Research has invested more than £300,000 into research projects investigating vitamin D deficiency in children of South Asian descent, as well as the link between pre-eclampsia and vitamin D.
Vitamin D deficiency in children of South Asian descent
Evidence suggesting a resurgence of vitamin D deficiency in the UK has highlighted how children from South Asian ethnic groups appear to be particularly vulnerable, resulting in a greater risk of poor bone health. Some vitamin D comes from food, but most of it is produced by the skin in sunlight.
Researchers from Manchester are looking into the impact of lifestyle factors, such as sun exposure, on vitamin D levels in South Asian children in the UK. It is hoped this could lead to new public health messages about sun exposure specifically for children with darker skin, with the ultimate goal of preventing vitamin D deficiency.
Public health campaigns in the UK encourage us to protect against skin cancer by limiting our summer sunlight exposure, staying in the shade, wearing protective clothing and using sunscreen. However, the darker someone’s skin, the more sun they need to produce sufficient vitamin D. Vitamin D deficiency during childhood can have lifelong consequences.
“Vitamin D is essential for healthy bones, especially during the growth spurt that occurs during adolescence,” explains lead researcher Professor Lesley Rhodes, adviser to the UK’s SunSmart campaign. “Prolonged vitamin D deficiency causes bones to be weak, making children prone to fractures. In severe cases it causes the bone deformity seen in rickets. There is also evidence to suggest that vitamin D might protect against some cancers, multiple sclerosis and diabetes.”
Around 125 children aged 12–15 of South Asian descent are taking part in the study. They will be monitored for one to two-week periods during each season of the year while wearing special badges to measure sun exposure. They are also keeping diaries of time spent indoors and out, their activities, clothing and food.
Pre-eclampsia and vitamin D
Pre-eclampsia is a common but potentially serious condition affecting up to eight per cent of pregnant women worldwide. A leading cause of death and illness in both mothers and babies, it’s characterised by high blood pressure, headaches, kidney problems, convulsions, stroke and life-threatening bleeding.
Despite its possible dangers it can go undiagnosed until the later stages, as warning signs often don’t present themselves until the condition has worsened. The only way to cure pre-eclampsia is to deliver a baby early, bringing its own risks, and a baby may then be worryingly small as a result of damage to the placenta that has impeded a baby’s growth. Thanks to Action funding, a team in Birmingham is now looking into possible links between vitamin D deficiency and pre-eclampsia.
Professors Mark Kilby and Shiao Chan are measuring vitamin D levels in blood and placentas, comparing levels in pregnant women with and without pre-eclampsia. The team is also researching whether vitamin D affects how the placenta develops and interacts with the mother’s blood vessels in the women during pregnancy. Vitamin D also appears important in influencing how the immune system works within the placenta.
“Estimates suggest one in six babies in special care units in the UK are there because their mother developed pre-eclampsia during pregnancy. Increasing evidence suggests there is an association between the condition and vitamin D deficiency,” says Professor Kilby. “Up to 95 per cent of pregnant women in the UK may have low vitamin D levels.”
It is hoped this work could eventually lead to clinical trials to find out whether taking vitamin D supplements during pregnancy helps prevent pre-eclampsia.