There's a lot of reasons why pregnant women are sometimes prescribed vitamin D. The American Pregnancy Association cites a 2010 study that requires pregnant women to get 4,000 IU of vitamin D daily to prevent preterm birth and other possible pregnancy complications such as gestational diabetes, preeclampsia, preterm birth, and low birth weight. (Note that some health agencies recommend only half of the dosage for fear of overdosing. Always consult with your OB-gyn to check your current vitamin D level and how much supplement you'll need, if any.)
Lack of vitamin D during pregnancy has also previously been linked to many different conditions including reduced bone density -- which can lead to abnormal bone growth, fractures, or rickets in newborns -- and asthma in babies especially those born to mothers who didn't have enough vitamin D while pregnant. In August this year, a U.K. study claimed that low levels of vitamin D in pregnancy could be associated to learning disabilites in kids.
Now, there is a new study that a lack of vitamin D in pregnancy could increase the chances of developing autism.
Researchers at The University of Queensland’s Queensland Brain Institute (QBI) in Australia found that pregnant women who had low vitamin D levels during their 20th week of pregnancy are more likely to have a child that exhibits more autism traits by the age of 6. Blood samples with a vitamin D reading of less than 25.0 nmols were considered deficient. The study, which was published in Molecular Psychiatry, examined approximately 4,200 blood samples from pregnant women and their children, who were closely monitored as part of the long-term "Generation R" study in Rotterdam, The Netherlands.
In a statement, QBI researcher professor John McGrath, who led the study alongside Dr. Henning Tiemeier from the Erasmus Medical Centre in the Netherlands, said, "This research could have important implications from a public health perspective. [It] provides further evidence that low vitamin D is associated with neurodevelopmental disorders."
"Just as taking folate in pregnancy has reduced the incidence of spina bifida, the result of this study suggests that prenatal Vitamin D supplements may reduce the incidence of autism," he added.
Vitamin D is not only vital in pregnancy, but it has also been proven to be crucial in a child's first year of life. In fact, doctors recommend vitamin D supplements even for breastfed babies. It helps the body absorb calcium, which is needed for a child's growing bones. Earlier this year, researchers at the Murdoch Children's Institute in Australia found a significant link between vitamin D deficiency in early childhood to asthma and other allergic disorders.
So how can you make sure you get enough Vitamin D for you and your baby? And how much do you really need when you're pregnant?
A regular vitamin D supplement only contains about 400 IU, so aside from getting healthy sun exposure (note the word “healthy” -- use sunscreen if necessary and avoid the sun's peak hours!), there are many foods that can fill one's daily vitamin D requirement. Fatty fish, like tuna, mackerel, and salmon are great sources of vitamin D as well as egg yolk, beef liver, and cod liver oil. Other foods may not naturally contain vitamin D but are fortified such as some dairy products (milk, cheese, and yogurt), orange juice, soy milk, and cereals. Read the labels to check.
You need all the nutrients you can get when you have a life inside you. So heed your doctor if he prescribes supplements like vitamin D.