Vitamin D Deficiency in Pregnancy. What’s Enough? It’s Implications to the World’s Second Most Dangerous Disease
Competency # 17. Knowing about Vitamin D
Reference: Am J of Clinical Nutrition, August 2006: 84, 350, Science: 311, 1717-73) and Journal Science. 2006, Mar 24 p 1770 – 3.
This study in the Netherlands looked at pregnant women from non-European backgrounds and measured their Vit D levels in their blood. They chose a very conservative level of “what’s enough” Vit D: > 25 nmols/L in your blood. That’s been our standard for years. It’s a level enough to keep you from getting rickets. What they found was alarming. Most “non Western” women had mean levels in the ranges of 15-20. Way low. Caucasian women had levels of 52.7. Living as far north as the Netherlands with limited sun from Nov-April, having cultural practices of remaining indoors and covered up, and having few dietary sources of Vit D were all considered part of the nutritional epidemic why non-Caucasian women were deficient.
We’ve all known that Vit D is important for bone growth. That’s the old news. The new science of Vit D is that it plays a dramatic role in many other functions in our body like muscle strength and immune response. There is also strong epidemiological linkages to Vit D and multiple sclerosis, colon cancer, rheumatoid arthritis and possibly multiple other cancers and insulin dependent diabetes. Even schizophrenia has been linked. Here is some hard science linking your immune system and Vit D. And the link for us to take home is to recognize our risks in relationship to this information.
What’s enough Vitamin D? In the Journal Science this year Dr. Liu et al describe the effect of Vitamin D in activating your immune system. Vit D “induces” or activates a protein called cathelicidin in macrophages. Dr. Liu showed that those macrophages (white blood cells that gobble up bacteria) could control and destroy the TB bacteria, but only when the serum Vit D level is above 80. Not 25. Now, tuberculosis is present in about 35% of the world’s population. It is not active in that many people, it is merely lying there waiting for the body to lose the ability to control it. But the statisticians tell us that health care workers are more likely to catch TB at work that HIV. And the HIV epidemic is uncovering more and more cases of drug resistant TB, such that a looming public health risk for all of us is polydrug resistant TB. That’s why having an immune system that is optimally operating is important to each and every one of us. And if its important to prevent you from getting a dramatically dangerous disease like TB, why isn’t it important when you get exposed to a cold virus on the door handle of the grocery store? Or the influenza virus sneezed on you at work? Dr. Liu’s seminal study shows a clear link between this simple little Vitamin and the optimal operation of our immune system. We need more Vit D. Period. A blood level of 25 is too low.
What we need to recognize is the risk we go through each and every year when we get to winter, and the sun goes down. As fall progresses, the angle of the sun is getting lower and the ability for our body to make Vit D from sunlight is gradually fading. Is that part of why we get more colds in winter? Your bones can make it through the winter by coasting on the reserves you have saved up in your fat tissue. But a growing baby, a growing uterus, a nursing mom?
And what if you’re pregnant, or have darker skin, or don’t drink milk, or always wear covering clothes, or never go out of doors? The Netherlands study suggested that pregnant non-Western women might need as much as 6000 IU a day.
WWW. What will work for Me? This author advocates at least 2000 IU a day for each and every one of us. And the AJCN study suggests we may need more when we are pregnant. If you know someone who is pregnant, please, please tell her to see her doctor and ask about extra Vit D. As for me, I’ve upped my daily goal to 2000 IU a day during the winter months. I’m starting Oct 1st. I want a blood level of 80.