The Skinny On: Vitamin D & Pregnancy

A few years ago my primary care physician started increasing my vitamin D intake.  Now, I’ve taken a multivitamin every day since I was 18 (well, since December it’s been a pre-natal vitamin) so I thought I was getting enough.  Both the regular vitamin and the prenatal vitamin have 400 IUs of vitamin D.  However, according to my doctor that wasn’t enough and she wanted me to add another 600+ IUs.  I didn’t ask a lot of questions, but remember her saying that it was to aid in the absorption of calcium and was essential for bone health.  Then last summer my mom told me that her doctor in PA had her taking vitamin D supplements as well (about 1,000 IUs).  She recalls it having something to do with osteoporosis prevention. (Turns out that women can’t absorb enough vitamin D from the sun after age 70.)  I remember finding it interesting that doctors were so focused on vitamin D intake, but just sort of filed it away.

Well vitamin D is in the news again, this time in regard to its importance to pregnant women.  According to a study published in the May issue of the American Journal of Obstetrics and Gynecology, pregnant women aren’t getting enough vitamin D.   Why is this important?  While vitamin D is crucial for bone health, it may also help decrease pre-term labor, preeclampsia and the need for c-sections, as well as cancer and cardiovascular disease later in life.  Many doctors also believe that a mother’s vitamin D intake during pregnancy can help her child, not only by strengthening their bones early on, but also by decreasing their chances of childhood MS and respiratory illness. 

Doctors who took part in the study believe that vitamin D levels have fallen due in large part to decreased outdoor activity and lifestyle.  Sounds about right since more and more women (and especially pregnant women) are trying to stay away from the sun to limit/minimize their skin cancer risk.  I know I am.  Although I try not to get too much sun anymore, I just didn’t have time when I was working at my office job.  I could go most days without spending more than 15-20 minutes outdoors-just enough time to grab a sandwich and get back to the office.  Globally, women in cultures that require their bodies to be covered are seriously vitamin D deficient.  Evidently, Saudi Arabia has a ridiculously high rate of women who are deficient in vitamin D; a result of wearing a hijab that covers more than 90% of their body.

However, getting enough vitamin D from the sun alone isn’t as easy as going outside.  According to one health educator in Seattle, to get enough vitamin D from the sun you need to be in the sun for at least 20 minutes a day with 40% of your body exposed WITHOUT sunscreen.  Not many of us can pull that off, nor do we want to from December to March!

So how much vitamin D do you need?  Most people need 1,000-2,000 International Units of vitamin D from either food, sunlight or supplements.  This recent study suggests that pregnant women need up to 10x that (2,000-4,000 IUs).  Prenatal vitamins alone usually have about 200-400 IUs.  Some years back it was thought that too much vitamin D would harm fetuses, but now researchers are saying no, the harm is in women not getting enough vitamin D.  

What can you do to ensure you’re getting enough vitamin D?  First check to see how much vitamin D you are already taking between your prenatal vitamins and calcium supplement (if you take one).  Then consider your diet -- what vitamin D rich foods (milk, eggs, fish) do you eat on a regular basis?  Also consider the amount of sunlight you get.  Then talk with your doctor.  If you’ve had blood work done in the past six months it’ll most likely show your vitamin D level.  If you haven’t had blood work done in a while talk to you doctor and find out if you should and if he/she would recommend increasing your vitamin D intake.   

I talked to my Ob/Gyn and she recommended that I take 800 IUs in addition to my prenatal vitamin.  Between the vitamins, my diet, and my sun exposure (I try to get out for a walk every day now that it's nice out) I probably get 2,000 IUs (more on the days when I am on a hard boiled egg kick...like today).  Based on my health, my doctor didn't seem worried and didn't up my vitamin D anywhere near the 4,000 IU level recommended in the study.  However,  if my vitamin D level drops, she'll adjust accordingly. 

So that’s the skinny on Vitamin D and pregnancy. 

Here's the NIH's list of vitamin D rich foods and how many IUs of vitamin D they have per serving:
http://ods.od.nih.gov/factsheets/vitamind.asp#h3


Sources: University of Colorado School of Medicine, CNN, Health.com, Mayo Clinic.