Dr Andrew Bremer, a Paediatric Endocrinologist and Chief of the Pediatric Growth and Nutrition Branch at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), part of the U.S. National Institutes of Health, details NICHD-supported research on vitamin D in pregnancy and early childhood development
Vitamin D, a hormone found in some foods and produced by the body after exposure to the sun, is important to our health in many ways: it helps the body build and maintain strong bones, plays a role in reducing oxidative stress and inflammation and helps our nervous system develop and carry messages from the brain to cells throughout the body. Vitamin D also helps the immune system fight off invading bacteria and viruses.
Vitamin D in pregnancy
Vitamin D deficiency during pregnancy has been linked to adverse pregnancy outcomes and may predispose women to gestational diabetes and preeclampsia. However, according to a recent NICHD study, sufficient levels of vitamin D before conception may play a protective role in pregnancy. Insufficient vitamin D levels were linked to miscarriage among women with a prior pregnancy loss. Researchers analysed data from about 1,200 women during preconception, attempting pregnancy and throughout the pregnancy. The study tracked time to pregnancy, pregnancy loss and live births. About half of the women enrolled in the study had sufficient vitamin D levels, while a little more than half had insufficient concentrations. Among women planning to conceive after a pregnancy loss, those who had sufficient levels of vitamin D were more likely to become pregnant and have a live birth, according to the analysis.
Another study linked vitamin D levels during pregnancy to birth weight and bone size of infants. Researchers found that among women who were overweight or obese before pregnancy, low vitamin D concentrations in both early and late pregnancy impacted fetal development. Considering that almost half of U.S. women entering pregnancy are overweight or obese, the authors wrote, prevention of low vitamin D concentrations in early and late pregnancy may optimise fetal growth.
Vitamin D in childhood
Scientists continue to discover new ways vitamin D supports health. A recent study found that infants or young children with low levels of vitamin D may have a risk of high blood pressure later in childhood or adolescence. Researchers analysed data from 775 children enrolled at birth in a long-term study of obesity risk factors. The children were followed until the age of 18.
Researchers measured vitamin D levels from blood samples taken at birth and in early childhood. The children’s systolic blood pressure (the top number in a blood pressure reading) was taken annually from ages three through 18.
Children with a low vitamin D level at birth had a 38% higher risk for elevated systolic blood pressure at ages six through 18, compared to children with a sufficient vitamin D level at birth. Children with a low vitamin D level at ages 1 to 3 had a nearly 60% higher risk of elevated systolic pressure from ages 3 to 18. If the study results are confirmed, treating pregnant women and young children for vitamin D deficiency may help reduce the risk of high blood pressure later in life
Given the many functions of vitamin D and the association of vitamin D deficiency with hypertension, diabetes mellitus, metabolic syndrome, cancer, autoimmune and infectious diseases, among other health complications, ensuring Vitamin D sufficiency in the population is a public health priority. Moreover, the association between maternal vitamin D status and health outcomes for the mother and her offspring highlight the potential ill-effects of vitamin D insufficiency through the generations.