INTRODUCTIONThe exact amount of vitamin D required for pregnant women to adequately supply the foetus during pregnancy is still unclear. This randomised trial attempted to determine the optimal dose of vitamin D necessary during pregnancy in order to attain a vitamin D level > 20 ng/mL in neonates. CONCLUSION A vitamin D3 dose > 50,000 IU/month is required during the second and third trimesters of pregnancy for vitamin D-deficient pregnant women in order for their neonates to achieve serum 25(OH)D levels > 20 ng/mL. Supplementation with < 50,000 IU/month is insufficient to ensure a vitamin D level > 20 ng/mL in all neonates born to vitamin D-deficient pregnant women. METHODS