This is a snippet of some info from The Vitamin D Newsletter dated 3 Dec 09.Scientists around the world presented their work at the recent Vitamin D conference in Brugge, Belgium. Many, but not all, of the scientists opined that we have to wait for randomized controlled trials (RCT) before recommending Vitamin D. In a future newsletter, I will review many of these presentations.
However, one was extraordinary. Professor Bruce Hollis presented findings from his and Carol Wagner’s five million dollar Thrasher Research Fund and NIH sponsored randomized controlled trials of about 500 pregnant women. Bruce and Carol’s discoveries are vital for every pregnant woman. Their studies had three arms: 400, 2,000, and 4,000 IU/day.
1. 4,000 IU/day during pregnancy was safe (not a single adverse event) but only resulted in a mean Vitamin D blood level of 27 ng/ml in the newborn infants, indicating to me that 4,000 IU per day during pregnancy is not enough.
2. During pregnancy, 25(OH)D (Vitamin D) levels had a direct influence on activated Vitamin D levels in the mother’s blood, with a minimum Vitamin D level of 40 ng/ml needed for mothers to obtain maximum activated vitamin D levels. (As most pregnant women have Vitamin D levels less than 40 ng/ml, this implies most pregnant women suffer from chronic substrate starvation and cannot make as much activated Vitamin D as their placenta wants to make.)
3. Complications of pregnancy, such as preterm labor, preterm birth, and infection were lowest in women taking 4,000 IU/day, Women taking 2,000 IU per day had more infections than women taking 4,000 IU/day. Women taking 400 IU/day, as exists in prenatal vitamins, had double the pregnancy complications of the women taking 4,000 IU/day.
What does this huge randomized controlled trial mean?We have long known that blood levels of activated Vitamin D usually rise during very early pregnancy, and some of it crosses the placenta to bathe the fetus, especially the developing fetal brain, in activated vitamin D, before the fetus can make its own.
However, we have never known why some pregnant women have much higher activated Vitamin D levels than other women. Now we know; many, in fact most, pregnant women just don’t have enough substrate, the 25(OH)D building block, to make all the activated Vitamin D that their placenta wants to make.
Of course fetal tissues, at some time in their development, acquire the ability to make and regulate their own activated Vitamin D. However, mom’s activated Vitamin D goes up very quickly after conception and supplies it to baby, during that critical window when fetal development is occurring but the baby has yet to acquire the metabolic machinery needed to make its own activated Vitamin D.
The other possibility, that this is too much activated Vitamin D for pregnancy, cannot stand careful scrutiny.
First, the amount of activated vitamin D made during pregnancy does not rise after the mother’s 25(OH)D reaches a mean of 40 ng/ml, so the metabolism is controlled.
Second, levels above 40 ng/ml are natural, routinely obtained by mothers only a few short decades ago, such as President Barack Obama’s mom probably did, before the sun scare. (President Obama was born in Hawaii in late August before the sun-scare to a mother with little melanin in her skin)
Third, higher blood levels of Vitamin D during pregnancy reduce risk of infection and other pregnancy complications, the opposite may be expected if 25(OH)D levels above 40 ng/ml constituted harm.
More found here