Calcium and Vitamin D in Obesity and Related Chronic Disease

There is a pandemic of lifestyle-related diseases. In both developed and lesser developed countries of the world, an inadequacy of calcium intake and low vitamin D status is common. In this chapter, we explore a mechanistic framework that links calcium and vitamin D status to chronic conditions including obesity, systemic inflammation, endothelial dysfunction, dyslipidemia and cardiovascular disease, and type 2 diabetes mellitus. We also update the available clinical evidence, mainly from randomized controlled trials, to provide a synthesis of evidence in favor or against these hypotheses. There is consistent data to support calcium increasing whole body fat oxidation and increasing fecal fat excretion, while there is good cellular evidence for vitamin D reducing inflammation. Clinical trials support a marginal reduction in circulating lipids and some meta-analysis support an increase in insulin sensitivity following vitamin D. However, these mechanistic pathways and intermediate biomarkers of disease do not consistently transcribe into measurable health outcomes. Cementing the benefits of calcium and vitamin D for extraskeletal health needs a reexamination of the target 25(OH)D level to be achieved and the minimum duration of future trials.