Endocrine Abstracts

Introduction: Vitamin D (Vit D) is required for maintaining optimal bone health and there is widespread campaign in the media for its use. There is however lack of awareness among the general public about therapeutic doses which if exceeded can result in harm. We present one such patient who was taking harmful quantities of vit D supplements procured over the internet which resulted in hypercalcaemia and renal failure.

Case Description: 50year old lady, Nutritionist with Type 1 DM and multiple previous fractures secondary to osteoporosis, presented with persistent abdominal pain and vomiting, no DKA. Severe Hypercalcaemia, 4.38 mmol/l was noted with suppressed PTH and AKI 3. No causes of secondary hypoparathyroidism evident from history and clinical examination. She reported taking Vitamin D, 8000IU daily for 5yrs; increased to 40,000IU (8x5000IU) daily 6months prior to admission. Her Vit D concentration was >900 nmol/l. The hypercalcaemia and AKI responded well to IV Fluids and a course of steroid treatment. Vitamin D normalised over 6 months.

Discussion: Vitamin D toxicity (VDT), Vitamin D levels >375 nmol/l, causing severe hypercalcaemia/hypercalciuria is rare and may result from excessive Vitamin D intake, defective metabolism or endogenous production of active Vit D metabolites as in lymphomas and granulomatous diseases. Our patient’s VDT was from the high Vit D intake.

Conclusion/Recommendations: Vitamin D deficiency is implicated in adverse outcomes for various health conditions; autoimmune disorders, COPD/cancer/pregnancy/ falls in elderly patients and lately COVID-19. These messages coupled with the easy availability of high dose vit D over the counter/internet is not always accompanied with clear information on the safe doses to use. VDT may become more common with increasing awareness of Vit D benefits but could be avoided if safe doses are clarified with improved regulation of over the counter sale of such suppliments.