Vitamin D in pregnancy: current perspectives and future directions. (June 2017)

• Record Type: Journal Article
• Authors: Kiely, Mairead; Hemmingway, Andrea; O'Callaghan, Karen M.
• Is Part Of: Therapeutic advances in musculoskeletal disease. Volume 9:Number 6(2017)
• Page Start: 145
• Page End: 154
• Publication Date: 2017-06
• Subjects: Vitamin D and pregnant women -- vitamin D requirements -- Neonatal vitamin D status; Musculoskeletal system -- Diseases -- Periodicals; Musculoskeletal Diseases -- Periodicals; 616.7
• DOI: 10.1177/1759720X17706453
• Languages: English
• ISSNs: 1759-720X

Abstract

As neonatal vitamin D status is determined by circulating maternal 25-hydroxyvitamin D [25(OH)D] concentrations, prevention of maternal vitamin D deficiency during pregnancy is essential for the avoidance of neonatal deficiency. However, a high prevalence of vitamin D deficiency has been extensively reported among gravidae and neonates from ethnic minorities and white populations resident at high latitude. Currently, regulatory authorities recommend vitamin D intakes for pregnant women that are similar to non-pregnant adults of the same age, at 10–15 µg/day (400–600 IU), to meet 25(OH)D thresholds of 25–50 nmol/liter. The lack of pregnancy-specific dietary recommendations is due to inadequate data indicating whether nutritional requirements for vitamin D during pregnancy differ from the non-pregnant state. In addition, there are few dose–response studies to determine the maternal 25(OH)D response to vitamin D intake throughout pregnancy at high latitude. These data are also required to determine vitamin D requirements during pregnancy for prevention of neonatal deficiency, an outcome which is likely to require a higher maternal 25(OH)D concentration than prevention of maternal deficiency only. With regard to the impact of vitamin D on perinatal health outcomes, which could guide pregnancy-specific 25(OH)D thresholds, dietary intervention studies to date have been inconsistent and recent systematic reviews have highlighted issues of low quality and a high risk of bias as drawbacks in the trial evidence to date. Many observational studies have been hampered by a reliance on retrospective data, unclear reporting, suboptimal clinical phenotyping and incomplete subject characterization. Current investigations of vitamin D metabolism during pregnancy have potentially exciting implications for clinical research. This paper provides an update of current dietary recommendations for vitamin D in pregnant women and a synopsis of the evidence relating vitamin D status with maternal and infant health.