Reduced absorption of tetracyclines, quinolones, and oral biphosphates with
concurrent use.

Calcium absoption may be reduced by corticosteroids,

Increased risk of  hypercalcemia, and metabolic alkalosis, with thiazide diuretics

High blood calcium level may increase the effect of cardiac glycosides.

Reduced ertotinib eficacy with calcium.

Increased risk of hypercalcemia with paricalcitrol.

Enzyme inducing antiepileptics increased the metabolism of Vitamin D

Fatal encephalopathy can occur in patients with renal failure when given calcium citrate
concurently due to marked levels in  Al levels 

Supplementation of Calcium and Vitamin D3

Constipation,     nausea,    abdominal pain,   hypercalcemia,

Hypercalcuria,   headache,   muscle weakness

Patients with hypercalcemia, hypercalcemia or hypophosphatemia,

Nephrolithiasis,   hypervitamonis  D

Indication-

Supplementation of Calcium and Vitamin D3

Dosage-

Calcium Citrate-
Adult-   expressed in terms of elemental calcium-
19- 50 years-  1000mg/day

> 50 years -  1200mg/day

Vitamin D3 - 10mcg/day for patients with limited sunlight exposure, low Vitamin D diet,
or bed ridden elderly patients

Take with or without food