I got my levels checked towards the beginning of my pregnancy, and the results came back very low. I've been learning a lot over the past couple weeks culminating in a phone conversation with Dr. Cannell from the Vitamin D Council himself this morning, and I thought I'd share some of what I've been learning.
-The National Institute of Health rejects research showing that Vitamin D might be important for anything other than bone health and recommends that you only need levels of 20+ ng/mL, but getting their RDA both for food and sunlight, I was still deficient, even by their standards, though most people have enough serum Vitamin D levels by this standard.
-The NIH also recommends that we need to supplement all exclusively breastfed babies with 400IU D3 to prevent rickets because most mothers do not have levels high enough to prevent deficiency in exclusively breastfed babies.
-Most organizations recommend higher serum Vitamin D levels. The standard is at least 30 ng/mL.
-The Vitamin D Council's recommendations are 50-80 ng/mL, on par or higher than most other organizations. Their reasoning is that most people who work outside have serum D levels between 50 and 80 ng/mL, probably as humankind has done throughout most of history.
-With serum D levels higher than 50 ng/mL, a breastfeeding mother will provide enough Vitamin D to her child in her breast milk (another sign that this is a good level).
-Dr. Cannell recommends 5000IU D3/day for pregnant and 6000IU D3 for breastfeeding mothers (or alternately, 5000IU for the breastfeeding mother and another 1000IU for the child) and 5000IU for the father.
-Dr. Cannell's recommended amounts are higher than the NIH's 4000 IU Upper Limit recommendations.
-I have not been able to hunt down any studies showing harm from Vitamin D supplementation under 200,000 IU/day, but let me know if you do.
-A good rule of thumb: If your shadow is longer than you are, you're not making much vitamin D from the sun.
-Your skin could theoretically make about 10,000 IU/day if you had enough skin showing for long enough during the right part of the day. Many factors influence how much you actually get from the sun, and the only way to tell if you are getting enough without supplements is to test your levels.
Please take this seriously. I'm not a supplements person, but I do think that Vitamin D levels are important. I think it's best to get enough from the sun, but as winter approaches, more and more of us may not be able to get enough from the sun, and I think supplements are better than going through the hell I've been through with my own DD's cavities, and I'm glad that's the worst we've had from our deficiency. There are many other risks from too little vitamin D. Do your own research and make your own decision on this, but I think it's something very important to be thinking about.