The increasing problem of subclinical and overt hypervitaminosis D in India: An institutional experience and review.

Objective: The aim of this study was to determine the changes in serum vitamin D distribution at an institute in India over the past 6 y and compare it with global trends.

Methods: We conducted an audit of 25-hydroxyvitamin D (25-OHD), calcium, and plasma intact parathyroid hormone (iPTH) reporting from January 2011 to February 2016. References for review were identified through searches of PubMed, Medline, and Embase for articles published until February 2016 using keywords "hypervitaminosis D" (MeSH Terms) OR "vitamin D toxicity" (All Fields) OR "vitamin-D intoxication" (All Fields).

Results: Reports of 25-OHD from 5527 patients were analyzed. Calcium and iPTH were available for 5501 (99.5%) and 1787 (32.3%) patients, respectively. Vitamin D deficiency and insufficiency were observed in 59.4 and 77.3%. Hypervitaminosis D (25-OHD >250 nmol/L) was noted in 225 (4.1%) patients, of whom 151 (2.7%) had vitamin D intoxication (25-OHD >375 nmol/L). We found that 46.22% (104 of 225) patients with hypervitaminosis D and 62.25% (94 of 151) with vitamin D intoxication had elevated calcium or suppressed iPTH. Orthopedic, pediatric, and surgery patients had the highest rates of hypervitaminosis D (7.9, 7.2, and 7% respectively; P < 0.001). An increasing trend for hypervitaminosis D was observed (1.48, 3.62, 3.90, 4.78, 6.21, and 7.82% in 2011, 2012, 2013, 2014, 2015, and 2016, respectively). A similar steady upward trend in 25-OHD has been reported in Ireland, England, Canada, and Australia. However, hypervitaminosis D reports are scant and have not increased over the years in the developed world.

Conclusion: There is a global secular trend of increases in 25-OHD over years. There is a disturbing trend of increased hypervitaminosis D at an Indian institute. Empiric, unmonitored, prolonged vitamin D supplementation, using non-recommended supraphysiological doses, especially when administered intramuscularly, should be discouraged.