CYP24A1 and Hypercalcemia: Nevertheless, as vitamin D is fat-soluble and thus, can accumulate in the body, it is theoretically conceivable that some individuals may develop symptoms of hypervitaminosis D (hypercalcemia) such as excessive thirst and urination, fatigue, nausea, and constipation if they additionally supplement vitamin D. In particular, individuals with the (very rare) condition of an abnormally functioning Vitamin D3 24-hydroxylase are at risk of hypercalcemia.