Vitamin D and pregnancy

A curious mother-to-be in a recent prenatal class asked how much vitamin D she should be taking during her pregnancy. First of all, this was a great question as it calls into question the importance of Vitamin D for everybody, not just pregnant mothers. Our understanding of the "vitamin" has expanded greatly in recent years. Previously it was mainly implicated in calcium regulation and bone health, and the recommended daily amounts were set with that function in mind. It is now understood that contrary to it's name, vitamin D is actually a steroid hormone that has direct effects on our immune system, pancreas, cardiovascular system, brain, muscle, and cell cycle regulation (whose dysregulation is central in the development of cancer). The previous recommendations for adequate intake are not sufficient to positively affect these other systems. Thus, it's deficiency has been linked to development of many chronic diseases including multiple sclerosis and cancers (breast, colon, prostate, ovarian, lymphomas, among others).

As with most medically related questions, there's no blanket answer that applies to every person. Factors such as ethnicity, age, sun exposure, and season all affect a person's vitamin D status. Here are the important factors to consider when contemplating supplementing this important vitamin:

1. Get your vitamin D levels checked by a health professional (Naturopath, MD, Nurse practitioner) who is up to date on current standards and recommendations. This is the BEST way to determine how much you need, and for how long. Each persons circumstances are different and individualized care is ideal.

2. Season. Here in British Columbia, even if it were sunny 365 days/year and you spent the entire year stark naked at Wreck Beach, the UV index wouldn't be high enough to generate Vitamin D most of the year. June-August are great, but beyond these months it's just not strong enough. Throughout the late fall - early spring, it's most likely a good idea to supplement Vitamin D. In the summer time, 10-15 minutes of midday sun can provide you with about 3 days worth of vitamin D.

3. Skin tone. Melanin is the pigment in skin that makes it dark. In dark skinned individuals this reduces their ability to produce Vitamin D from sunlight.

4. The safe "Tolerable Upper Intake Level" established by the Food and Nutrition board of the National Research Council (in the USA) is 2000 IU per day. That's to say healthy people taking 2000 IU/day are unlikely to experience any adverse effects. Although some now are considering this to be too low, it is a well established level that would apply to most people north of California.

5. Vitamin D3 is a more active form than D2, so go with that one if given the choice. Also, it is a fat soluble vitamin, which means that if you take it with food that contains some fat (olive oil, etc..) it will help your body absorb it. For the pregnant mothers out there, be cautious with some food sources of vitamin D, as some can be harmful to the fetus. Cod liver oil for example, contains large amounts of vitamin A (which is also a steroid hormone) that can cause birth defects.

In conclusion, I want to reiterate the importance of consulting a health professional for specific advice regarding dose and form. The information presented here is intended educate on the importance of vitamin D, and to provide some basic understanding on how we get it. Hope this has been helpful,

B