Related Experiment Video
Updated: Dec 28, 2025

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
Hypervitaminosis D without toxicity
Jasmin Rahesh1, Victoria Chu1, Alan N Peiris1,2
1School of Medicine, Texas Tech University Health Sciences CenterLubbockTexas.
Abstract:
Vitamin D deficiency is highly prevalent and there are an increasing number of reports of vitamin D toxicity, mostly related to the misuse of over-the-counter supplements. We report a case with marked hypervitaminosis D (25(OH)D 196 ng/mL) without clinical or biochemical toxicity and normal serum calcium, phosphorus, and 1,25(OH)2D levels. The decline and normalization of the patient's 25(OH)D and urine calcium after cessation of supplements indicated that these supplements were the likely etiology of her hypervitaminosis D. Over-the-counter medications would benefit from regulation by the Food and Drug Administration to prevent incidental toxicity, as seen in our patient.
Related Concept Videos
Vitamins
Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin...
Role of Vitamins in Maintaining Bone Health
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
Renal Failure: Dose Adjustments
Reduced renal clearance and elimination rate are common outcomes of renal impairment. These alterations lead to a prolonged elimination half-life and an altered apparent volume of distribution for drugs. As a result, dosage adjustments are typically necessary to maintain optimal drug levels in the body.
However, dosage adjustments...
Connective Tissue Cell Types
Fat cells (adipocytes), smooth muscle cells (myoblasts), and bone cells (osteoblasts) are some connective tissue cell types. Some immune system cells...
Teratogenicity

