Trial Information

Vitamin D Status of Pregnant Women and Their Children in Eau Claire, South Carolina: A Prevalence and Supplementation Model for Community Health Care Centers in the U.S.

With avoidance of sunlight exposure due to lifestyle changes and concerns regarding skin
cancer and the resultant widespread use of sunscreen, very few Americans are meeting their
needs for vitamin D either through skin photosynthesis or dietary intake. A study published
by the Centers for Disease Control (CDC) and our laboratory at the Medical University of
South Carolina (MUSC) revealed that 42% of African American women in their childbearing
years exhibited a deficiency of D vitamin (hypovitaminosis D) (1). Using new guidelines of
optimal vitamin D levels, more than 90% of African American women now suffer from vitamin D
deficiency (2). Science News (October 2004) called vitamin D deficiency a "silent epidemic"
in America, with no group unaffected (3). Deficiency during pregnancy has profound effects
on the developing fetus. Vitamin D deficiency affects other systems besides bones: it is
associated with later, lifelong sequelae, with notable increased risk of autoimmune diseases
such as rheumatoid arthritis (4), multiple sclerosis (5,6), type I diabetes (7,8), and
certain cancers (7,9-14). Prevention and intervention studies only recently have been
undertaken (3). A reexamination of dietary vitamin D requirements of various vulnerable
populations in the U.S. is desperately needed (2,3). As a representative community with a
diverse population, Eau Claire Cooperative Health Centers in South Carolina (ECCHC) serves a
large percentage of African American as well as Caucasian and Hispanic women and children
considered to be at high risk for vitamin D deficiency. ECCHC has eight clinics providing 1o
care services to patients with special emphasis on Pediatric and OB/GYN services. Defining
the prevalence of vitamin D deficiency in this patient population and the optimal vitamin D
supplementation strategies for these women and their infants will become the prototype for
recommendations applicable to other communities throughout the U.S.

In Specific Aim 1, the vitamin D status of a cross-sectional sample of 1000 pregnant women
presenting at ECCHC for their prenatal care will be determined by measuring serum calcium,
phosphorus, intact parathyroid hormone (iPTH), 25(OH)D, the nutritional marker of vitamin D
as a function of ethnicity. Maternal health characteristics, skin pigmentation (using
reflectance spectrophotometry), dietary characteristics (using an established food frequency
questionnaire), and lifestyle profiles (using standardized questionnaires) will be
ascertained as well. Any deficiency noted will lead to specific recommendations for vitamin
D supplementation by the research team, with standardized strategies to monitor status
following initiation of supplementation in Specific Aim 2. Based on extensive preliminary
data, a supplementation regimen will be implemented and its efficacy in achieving optimal
vitamin D status in these women tested in Aim 2: women within three racial groups (African
American, Hispanic and Caucasian) will be stratified into two groups by their initial
25(OH)D level: Group 1, <32 ng/mL (less than optimal vitamin D status) and Group 2, ≥32
ng/mL (optimal vitamin D status). Based on our ongoing NIH study of pregnant women, each
group will be randomized to receive one of two doses starting at 13 weeks' gestation: 2,000
or 4,000 IU vitamin D3/day after a universal one-month 2,000 IU/day dosing run-in period at
12 weeks' balanced by race/ethnicity. The randomization schema allows determination of both
efficacy and safety for those deficient and those replete at entry into the study as a
function of race/ethnicity and season.

Anticipated Results and Future Studies: We expect to observe vitamin D deficiency in a
considerable percentage of the mothers and their newborn infants who receive care at ECCHC,
especially those individuals with darker pigmentation. In Aims 1 & 2, by determining the
prevalence of vitamin D deficiency with each racial/ethnic group, we will establish
guidelines for supplementation and health maintenance, and policy recommendations for the
dietary recommended intake of vitamin D in the U.S. The results will allow us to implement
specific dietary and/or medical interventions aimed at correcting hypovitaminosis D in the
population in this study and other similar populations being served by the more than 1000
community health centers nationally.