Getting Vitamin D During Winter

a blog by Bree Johnson, MS, RD, Pulling Down the Moon, November 18, 2010

As we head into the winter chill in the Midwest we know that we won’t be seeing the warm summer months for at least half a year! Something else that also vanishes is the “sunshine vitamin” also known as vitamin D. From early October to April, above the 37th degree latitude, people cannot synthesize vitamin D in their skin because the sun is too far away.

Vitamin D Deficiency

In recent years, vitamin D deficiency has been found to be associated with increased rates of bone fractures, cancer, autoimmune diseases, depression (especially Seasonal Affective Disorder), cardiovascular disease, diabetes and the flu, to name a few.

In addition, vitamin D has been found to be lower in the follicular fluid of women with infertility, and women with higher follicular fluid levels had increased IVF success rates (Ozkan et al, 2009). We also know that, especially among women with PCOS and/or infertility, depression rates are very high.

Vitamin D plays an equally important role in pregnancy, as vitamin D deficiency has been associated with increased rates of bacterial vaginosis (Bodnar et al, 2009), which effects 1 in 3 women of reproductive age, and can cause preterm labor. Vitamin D is also very important in building bones in utero and for preserving the bone mass of the mother. Maternal diet (especially of vitamin D) appears to modulate bone mineral acquisition during intrauterine life (Cooper et al, 2009). Vitamin D deficiency also correlates with preeclampsia, gestational diabetes, and an increased risk for C-section delivery.

Get Tested for Vitamin D Deficiency

Due to the lack of research in replenishing vitamin D stores while pregnant, it’s advised to have adequate vitamin D stores prior to pregnancy and then supplement with low levels of vitamin D during pregnancy.

The best thing about vitamin D is that through a simple blood test (vitamin D 25-OH) done by your primary care physician, you can find out if you are deficient. If your levels are below 30 ng/ml (per most labs), it is considered a deficiency and you should be supplementing with vitamin D to correct your levels.