Overdosage of β-carotene caused its accumulation in the body as a reversed source of vitamin A and an antioxidant. Adverse effect due to β-carotene overdosage is carotenemia which is a harmless condition with a slightly yellow discoloration in the skin and will disappear upon discontinuation of β-carotene.
Overdosage of selenium has been associated with loss of hair, nail changes, diarrhoea, dermatitis, metallic taste, garlic odour of breath, irritability and fatigue.
Overdosage of vitamin E (>1200 IU daily) may cause diarrhoea, abdominal pain, gastrointestinal disturbances, fatigue, dizziness.
Overdosage of vitamin C may cause renal calculi, nausea, gastritis and diarrhoea. Diuresis with forced fluids may be useful following a massive ingestion.