Role of plasma calcium, phosphorus, alkaline phosphatase, and parathyroid ‎hormone in the prediction of vitamin D deficiency

Vitamin D deficiency is a highly prevalent medical condition associated with various clinical and biochemical outcomes although these outcomes might be absent in a significant percentage of patients. Altered serum calcium, phosphorus (PO4), parathyroid hormone (PTH) and alkaline phosphatase (ALP) activity are expected but not proven by various research. The current study aims to investigate the possibility of these biomarkers to be used as indicators of vitamin D deficiency or insufficiency. The study enrolled 150 randomly selected participants who have no acute or chronic medical condition with various levels of serum vitamin D ranging from normal to severely deficient. They were investigated for serum total calcium, PO4, PTH, and ALP activity. The results were statistically compared among the studied groups and correlated with serum vitamin D levels. There was no significant difference in mean serum calcium, PO4, and ALP activity among the groups with poor correlation with vitamin D. Mean serum PTH has shown a significant difference among the studied groups with a strong negative correlation with vitamin D. This difference was apparent even in patients with vitamin D insufficiency. Serum calcium, PO4 and ALP activity seem to have a poor correlation with vitamin D concentration. In addition, serum PTH might be considered a sensitive marker of both vitamin D deficiency and insufficiency.