Vitamin D is known as the “sunshine” vitamin because it is formed in the body by the action of the sun’s ultraviolet rays on the skin. The fat-soluble vitamin is converted in the kidneys to the hormone calcitrol, which is actually the most active form of vitamin D. The effects of this hormone are targeted at the intestines and bones. Decreased vitamin D intake along with not enough sunlight exposure can cause a vitamin D deficiency. Other causes could be inadequate absorption and impaired conversion of vitamin D into its active form. When vitamin D deficiency occurs, bone mineralization is impaired which leads to bone loss.

Vitamin D is important for the growth and development of bones and teeth. For this reason, vitamin D is an important growth nutrient for infants and children. Vitamin D is one of the primary regulators of calcium absorption, which is also important for proper bone health and development. Deficiencies are frequently found in individuals with or at risk for osteoporosis. Considering this relationship, vitamin D insufficiency may have an effect on bone strength.

Maternal vitamin D levels may be responsible for programming neonatal skeletal development. The purpose of a recent study was to determine the association of mothers’ vitamin D status with bone variables of their newborns. The cross-sectional study included 125 pregnant women. Researchers collected data from each of the participants, which included age, body mass index before pregnancy, pregnancy weight gain and total vitamin D intake. The researchers also collected blood samples from the mothers during the first trimester, two days postpartum and from the umbilical cords at birth to analyze serum 25-hydroxyvitamin D. It was found that although the mean total intake of vitamin D among the mothers met current recommendations, 71 percent of women and 15 percent newborns were deficient during pregnancy. These results suggest that efforts should be made to revise current nutrition recommendations for pregnant women since this may have a permanent effect on the well-being of their children.1

1 Viljakainen HT, Saarnio E, Hytinanttis T, et al. Maternal vitamin D status determines bone variables in the newborn. J Clin Endocrinol Metab. Apr2010;95(4):1749-57.