Vitamins and mineral salts are involved in numerous biochemical reactions such as enzyme.

Allergic reactions viz skin rashes and gastrointestinal disturbances such as nausea, vomiting, diarrhoea or constipation may occur. A generalized flushing and a feeling of warmth has been reported following nicotinamide therapy. Vitamin C: Large doses may cause diarrhoea and other gastro-intestinal disturbances and are associated with the formation of renal calcium oxalate calculi. Vitamin C should be given with care to patients with hyperoxaluria. Tolerance may be induced with prolonged use of large doses. Vitamin D: Should not be administered to patients with hypercalcaemia, and be given with caution to infants, as they may have increased sensitivity to its effects.