Vitamin D Status of Pregnant Women and Their Children in Eau Claire, South Carolina

Overview

Science News (October 2004) called vitamin D deficiency a "silent epidemic" in America, with no group unaffected. Using new guidelines of optimal vitamin D levels, more than 90% of African American women now suffer from vitamin D deficiency. Deficiency during pregnancy has profound effects on the developing fetus. Other systems besides bones are affected by vitamin D deficiency, including an increased risk of autoimmune diseases such as rheumatoid arthritis, multiple sclerosis, type I diabetes, and certain cancers. This study proposes to examine and manage vitamin D levels in more than one thousand women in an underserved population in South Carolina. The women will be from the patient population seeking OB/GYN and Pediatric services through Eau Claire Cooperative Health Centers, Inc. (ECCHC), a network of ten clinics in three counties in the center of the state approximately 70 miles from Charleston, SC. ECCHC is one of approximately 1000 community health centers supported through Health and Human Services' (HHS) Health Resources and Services Administration's (HRSA), Bureau of Primary Health Care. The research objectives for this project will be managed through the Pediatric Nutritional Sciences Research Center of the Children's Research Institute at the Medical University of South Carolina, Charleston, SC, in collaboration with ECCHC. The research aims will evaluate vitamin D levels and possible contributing factors to the levels in pregnant women. Women who present to ECCHC within the first trimester of pregnancy will be randomized to one of two doses of vitamin D supplementation shown to be effective in other groups. Each pregnant mother will begin supplementation during the 12th week of pregnancy and will be followed closely throughout pregnancy for one year to determine the effectiveness of supplementation on vitamin D status, overall health of mother, and of her infant following delivery. We expect to observe severe vitamin D deficiency in a considerable percentage of the mothers and their infants who receive care at ECCHC, especially those individuals with darker pigmentation. When the extent of vitamin D deficiency within each racial/ethnic group is better defined and their supplementation requirements identified, we will be better able to establish guidelines for supplementation and health maintenance, and set policy recommendations for the dietary recommended intake of vitamin D. Those women and their infants identified as deficient in vitamin D will be important in establishing community health care policies for vitamin D surveillance and supplementation strategies. 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.

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.