The drug can reduce the absorption of estramustine, etidronate and other bisphosphonates, phenytoin, quinolones, oral tetracycline antibiotics and preparations of fluoride. The interval between taking the tablets "Calcium + Vitamin C" and the above drugs should be at least 3 hours.
Simultaneous administration of vitamin A D and its derivatives increases the absorption of calcium.
Absorption of calcium from the digestive tract can decrease with the simultaneous intake of certain types of food, for example, spinach, rhubarb, bran, and cereals.
When administered in high doses along with vitamin D and its derivatives of calcium can reduce the effect of verapamil and, possibly, other calcium channel blockers. Oral administration of high doses of calcium to patients receiving digitalis preparations may increase the risk of arrhythmias.
Thiazide diuretics reduce the excretion of calcium in the urine. Therefore, one should keep in mind the risk of developing hypercalcemia in their simultaneous use with effervescent tablets "Calcium + Vitamin C".