Certain dietary substances interfere with the absorption of calcium. These include oxalic acid (found in large quantities in spinach), phytic acid (bran and whole cereals) and phosphorus (milk and other dairy products).
Administration of corticosteroids may interfere with calcium absorption.
Calcium enhances the effects of digitalis on the heart and may precipitate digitalis intoxication. Calcium salts reduce the absorption of tetracyclines.
When calcium is administered in large amounts for long periods hypercalcemia and hypercalciuria may result. This is most likely to occur in patients with hypoparathyroidism who are receiving high doses of Vitamin D.
Calcium salts should be given cautiously to patients with impaired renal function or a history of renal stone formation.
It is also not intended for treatment of severe specific deficiency.
Care should be taken when given to patients with iron shortage or iron absorption diseases, haemoglobinopathies or existing gastro-intestinal disease.
The absorption of iron is inhibited or decreased in the presence of antacids containing carbonates, magnesium trisilicate or when taken with tea. Iron salts appear to reduce the effects of penicillamine.
The absorption of iron salts and tetracyclines is diminished when they are taken concomitantly by mouth.
This product is not intended for treatment of pernicious anaemia or other megaloblastic anaemias where Vitamin B12 is deficient. Neurologic involvement may develop or progress, despite temporary remission of anaemia, in patients with Vitamin B12 deficiency who receive supplemental folic acid and who are inadequately treated with Vitamin B12.
This product is not intended for treatment of severe specific deficiency.
Pyridoxine may decrease the efficacy of levodopa in the treatment of parkinsonism.
Therefore it should be used with caution for patients undergoing such therapy.