Vitamin D Status During Pregnancy Affects Birth Outcomes

In this study, researchers in The Netherlands measured vitamin D levels in mothers' blood in their second trimester and levels in the umbilical cord after they gave birth.  They also used techniques like ultrasounds to assess babies during pregnancy.  They found that mothers with lower vitamin D levels in their blood gave birth to babies with smaller heads, shorter body lengths, and lower weights.  They also found that mothers with the highest levels of vitamin D had the lowest risk of delivering babies pre-term, babies that had low birthweight, and for delivering babies of small size for their gestational age.  Finally, after mothers gave birth, higher levels of vitamin D in the umbilical cord were associated with higher birth weight and weight for gestational age.  They also found that mothers with high vitamin D levels in their blood produced cords with high levels.  These results could not definitively say that vitamin D causes better birth outcomes, because this was only an observational study.  However, they measured ethnicity, diet, nutrient intake, smoking, alcohol use, and many other factors that affect birthing outcomes, and the results still remained significant.

So, what are the take aways?  Basically, having more vitamin D in the blood during pregnancy and in the umbilical cord are associated with having healthier babies.  Mothers with more vitamin D give birth to babies later in their pregnancies that have bigger heads, more weight, and longer length.  All of these things help to prevent children from developing chronic disease later in their lives.  The authors suggested increasing vitamin D levels in The Netherlands, but I think that mothers everywhere would benefit their babies if they increased their vitamin D.  So, taking folic acid and vitamin D supplements may be a good idea for you mothers out there.  You can also spend some time in the sun (since your skin can produce vitamin D when exposed to UV light) and eat foods high in vitamin D like mushrooms, eggs, fish (low in mercury), liver, and foods fortified with vitamin D (like milk and cheese).

If you want to read more about this topic, the article I used was called Maternal vitamin D concentrations during pregnancy, fetal growth patterns, and risks of adverse birth outcomes, and it was published in The American Journal of Clinical Nutrition.  

Disclaimer: I do not take credit for discovering or owning any of this information, but I wish to spread it in an understandable, useful way.