AHRQ Findings by Life Stage for Vitamin D and Calcium for Clinical Outcomes of Bone Health*
0–6 months: Not reviewed
7 months–2 years: Not reviewed
3–8 years: Not reviewed
9–18 years: Not reviewed
19–50 years: The AHRQ-Ottawa report concluded that supplementation with vitamin D (most studies used vitamin D3) plus calcium is effective in reducing the risk of fractures in institutionalized populations. One RCT of female Navy recruits ages 17 to 35 years showed that vitamin D (800 IU/day) in combination with calcium (2,000 mg/day) supplementation can reduce the risk of stress fractures from military training compared with placebo.
51–70 years: No new data were identified in the AHRQ-Tufts report
≥ 71 years: No new data were identified in the AHRQ-Tufts report
Pregnant and lactating women: No data
SOURCE: Modified from Chung et al. (2009).
Pregnancy and lactation constitute specific, unique life stages that are of current interest regarding calcium and vitamin D functions and nutritional requirements. The body of evidence concerning skeletal health as it relates to the calcium and vitamin D nutriture of pregnancy, lactation, and fetal development is integrated below so as to provide context for the selection of indicators for DRI development.
Pregnancy: Calcium The developing fetus requires calcium, especially during the third trimester when the skeleton is undergoing mineralization. Direct measurements of the calcium content of the newborn skeleton have indicated that 25 to 30 g of calcium is transferred to the fetus by the end of gestation (Givens and Macy, 1933; Trotter and Hixon, 1974). Maternal intestinal calcium absorption doubles beginning early in pregnancy even though little calcium is transferred to the embryo at this stage (Heaney