groups. Although there is a solid body of evidence related to bone health and the role of calcium and vitamin D, many data gaps remain for younger age groups and for the effect under menopausal conditions. The issue of “calcium economy” among certain groups and ethnic differences in vitamin D utilization require attention.
Elucidate inter-relationship between calcium and vitamin D, and specify independent effect(s) of each. There is a need for research protocols that examine the effects of vitamin D and calcium separately rather than as a combined administration, and which better clarify the nature of the inter-relationship. Without such data, the ability to identify requirements for calcium and for vitamin D is challenging.
Explore causal role for vitamin D in non-skeletal health outcomes. Investigation of causal relationships between vitamin D nutriture and potential non-skeletal health outcomes should undergo further research. These may include but are not limited to (no particular order): immune function and anti-inflammatory effects (especially related to obesity); total and site-specific cancers; cardiovascular disease; and diabetes. More data on the role of calcium and vitamin D, and their metabolism, during pregnancy and lactation is needed.
Determine appropriateness of serum 25-hydroxyvitamin D (25OHD) as a biomarker of effect. The ability to use the relatively accessible measure of serum 25OHD as a biomarker or surrogate is limited by a number of factors including not only its role as a prohormone, but also its variability, which is due to a number of non-nutritional factors. A better understanding of its relationship to specific health outcome would be beneficial, enhancing both the quality and quantity of research available. The measure should be studied for this purpose and also should be subject to a formal validation process.
Elucidate the effect of genetic variation, including that among racial/ethnic groups, and epigenetic regulation of vitamin D on developmental outcomes. This is an emerging field of study, which will likely prove relevant to DRI development. Studies in this area may contribute notably to an understanding of population differences related to chronic disease risk.
Develop innovative methodologies to provide for identification and assessment of adverse effects of excess calcium and vitamin D. The ability to study adverse effects of calcium and vitamin D is