Uses

Indicated for treatment of hypoparathyroidism, refractory (vitamin D–resistant) rickets, and familial hypophosphatemia. Used to correct vitamin D deficiency.

Do not use if

Contraindicated in hypercalcemia, malabsorption syndromes, known hypersensitivity to vitamin D, and hypervitaminosis D.

Side effects

Hypervitaminosis D may occur with excessive doses, manifesting as hypercalcemia, polyuria, nocturia, polydipsia, renal impairment, nephrocalcinosis, vascular calcification, and CNS effects including mental disturbances.

Warnings

Hypersensitivity to vitamin D may cause hypercalcemia in infants with idiopathic hypercalcemia; vitamin D must be strictly restricted in such cases. Keep out of reach of children.

How it works

Ergocalciferol (vitamin D2) undergoes two-step hydroxylation: first in the liver to 25-hydroxyvitamin D, then in the kidneys to 1,25-dihydroxyvitamin D (calcitriol), the active form. It promotes intestinal absorption of calcium and phosphorus, maintaining serum mineral homeostasis.

Storage

Store in a cool, dry place; protect from light and moisture. Specific storage conditions depend on formulation.