A fixed-dose combination supplement containing elemental calcium (as calcium carbonate) and cholecalciferol (Vitamin D3). It is a cornerstone therapy for the prevention and treatment of calcium and vitamin D deficiencies, which are highly prevalent in the Indian population due to dietary habits, skin pigmentation, and limited sun exposure. It is essential for bone mineralization, neuromuscular function, and numerous cellular processes.
Adult: One tablet (1000mg Calcium + 200IU Vitamin D3) once or twice daily, as directed. Typically one tablet daily for prevention, one tablet twice daily for treatment of deficiency. Should be taken with or after food.
Note: Take with a full glass of water, preferably with or after a meal to enhance absorption and reduce gastric irritation. Do not take with high-fiber meals or foods containing oxalic acid (spinach) or phytic acid (whole grains) as they can bind calcium. Space by at least 2 hours from other medications like tetracyclines, bisphosphonates, levothyroxine, and iron supplements.
This combination works synergistically. Calcium provides the essential mineral for bone hydroxyapatite formation and various physiological functions. Vitamin D3 enhances intestinal absorption of dietary calcium and phosphate, promotes renal reabsorption of calcium, and regulates bone remodeling by stimulating osteoclast differentiation for bone resorption and osteoblast activity for bone formation, maintaining calcium homeostasis.
Pregnancy: Category A (US FDA). Considered safe. Recommended for all pregnant women in India (ICMR guidelines) to meet increased fetal demand (RDA: 1000-1300 mg Calcium, 600 IU Vitamin D). Prevents neonatal hypocalcemia and maternal bone loss.
Driving: No known effects on driving ability.
| Bisphosphonates (Alendronate, Ibandronate) | Calcium significantly reduces absorption of bisphosphonates. | Major |
| Levothyroxine | Calcium carbonate impairs absorption of levothyroxine. | Major |
| Oral Tetracycline & Fluoroquinolone Antibiotics | Calcium forms insoluble chelates, reducing antibiotic absorption. | Moderate |
| Oral Iron Supplements | Calcium can inhibit iron absorption. | Moderate |
| Thiazide Diuretics (Hydrochlorothiazide) | Increased risk of hypercalcemia due to reduced renal calcium excretion. | Moderate |
| Cardiac Glycosides (Digoxin) | Hypercalcemia potentiates digoxin toxicity, risking serious arrhythmias. | Major |
| Corticosteroids (Prednisolone) | Reduce calcium absorption and increase excretion. | Moderate |
| Orlistat | May reduce absorption of fat-soluble Vitamin D. | Moderate |
| Anticonvulsants (Phenytoin, Carbamazepine) | Increase metabolism of Vitamin D, leading to deficiency. | Moderate |
Same composition (Calcium (1000mg) + Vitamin D3 (200IU)), different brands: