Well what do you know. Turns out giving someone 600.000 IU of Vit D may not be good for them.
Vitamin D has achieved increasing prominence over the past few decades in the research publications. 1,25(OH)2D3 is now considered to be a steroid hormone and functions the same way as other steroid hormones by interacting with its vitamin D receptor (VDR). Over the past several decades, various research has shown that the VDR is widely distributed among various body tissues than previously thought (intestine, bone, kidney, and parathyroid).[2] The pluripotent steroid hormone 1,25(OH)2D3 initiates the physiologic responses of at least 36 cell types that possess the VDR. In addition to the production of circulating 1,25(OH)2D3 in the kidneys, researchers have found a paracrine production of this steroid hormone in at least 10 extra renal organs.
Vitamin D has been found to have important role the adaptive immune system, the innate immune system, insulin secretion by the pancreatic β cell, myocardial functioning, blood pressure regulation, and brain and fetal development.[2] Vitamin D depletion has been associated with increased risk of osteoporosis, hip fracture in the elderly, hypertension, cardiovascular disease, and some types of malignancies.[1] Vitamin D deficiency prevails in epidemic proportions even in a tropical country like India, with a prevalence of 70%–100% in the general population.[3] Therefore, it is not surprising that vitamin D supplements are being prescribed for various diseases. Many patients are given vitamin D supplements empirically in doses much beyond the recommended doses, without the laboratory evidence of vitamin D deficiency and without monitoring.
In patients taking vitamin D preparations monitoring should be done by periodic estimation of 24-h urinary calcium excretion, which should not exceed 250 mg.[4] Vitamin D is toxic in huge doses and reports of vitamin D toxicity exist in literature.[5] Vitamin D intoxication usually occurs at levels of 25(OH) vitamin D > 150 ng/mL.[6] The clinical manifestations are kidney disorders (65.0%), renal insufficiency (51.0%), gastrointestinal tract disorders (23.0%), and arterial hypertension (52.0%).[7]
The management of these patients includes withdrawal of the offending agent/s, intravenous volume expansion, furosemide, bisphosphonates and hydrocortisone in selected cases. Complete recovery of renal function can occur if the diagnosis is made early in the course of the disease.
In our patient, hypercalcemia was parathyroid independent, as the serum levels of PTH was low normal. The malignancy as the cause of hypercalcemia was ruled out by absence of clinical and laboratory evidence of malignancy.
http://www.ncbi.nlm....les/PMC4311368/