A significant number of Americans are deficient in Vitamin D, including pregnant women. According to a recent reanalysis of the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2008, 99% of U.S. adults do not consume the recommended dietary allowance (RDA) for Vitamin D. A variety of health problems have been linked to Vitamin D deficiency. A new study, conducted by researchers at the University of Pittsburgh, has found that Vitamin D deficiency increases the risk for a small for gestational age infant. They published their findings in the January 2014 edition of the journal Obstetrics & Gynecology.
Worldwide, small for gestational age newborns are a major public health issue. A small for gestational age newborn is often due to fetal growth restriction, which in turn due to an inadequate supply of nutrients to the developing fetus. These fetuses are at an increased risk of death before birth. After birth, they are at increased risk of serious health problems; sadly, these problems are not limited to infancy, they persist into adulthood. The researchers note that a number of factors can result in a small for gestational age infant; these include nutritional status, obesity, age, smoking, and infection.
The investigators conducted a study to assess the association between second-trimester maternal serum Vitamin D concentrations and risk of small for gestational age infant among women pregnant with a single fetus. The study group comprised 792 women who were at high risk of preeclampsia (toxemia); the women were enrolled in a multicenter trial in which they received low-dose aspirin with the goal of reducing the risk of preeclampsia. The women had blood samples drawn between 12 and 25 weeks of gestation to measure serum Vitamin D levels. A small for gestational age infant was defined as as one with a birth weight below the 10th percentile for gestational age.
The researchers found that 13% of the newborns were small for gestational age. Vitamin D concentrations were lower in women who delivered a small for gestational age infant. Women with normal Vitamin D levels had a 43% decreased risk of delivering a small for gestational age infant. White women with a normal vitamin D level had a 68% reduction in risk and non-obese women with a normal Vitamin D level had a 50% reduction in risk. There was no association Vitamin D levels in black or obese women. The authors concluded that maternal Vitamin D status in the second trimester (middle three months of pregnancy) is associated with risk of delivering a small for gestational age infant among all women and in the subgroups of white and non-obese women.
Take home message:
Vitamin D is unique among the essential vitamins because it can be produced by the skin with exposure to sunlight body subcutaneously after exposure to ultraviolet B radiation. Thus, Angelenos, due to residing in the Sunbelt can amp up their Vitamin D levels by merely going out in the sun. However, many women avoid sun exposure for fear of skin damage, including skin cancer. Prenatal vitamins typically contain Vitamin D. Check the amount listed on the bottle and add a supplement if necessary. The RDA for Vitamin D is 1,000 milligrams daily; do not exceed 2,500 mg. Excess vitamins can be harmful.