Health information you can trust
Our index of medical information authored by professionals
Join the discussion in our forums
Drug treatments, dosage instructions and side effects
Information for medical professionals
Assess your symptoms online with our free symptom checker.
Vitamin and mineral deficiencies are usually caused by low dietary intakes or by certain medical conditions, such as those affecting absorption from the gut. Once a deficiency is diagnosed, it is often a straight-forward case of replacing the missing vitamin or mineral with a supplement. Iron tablets, calcium tablets, vitamin D tablets and vitamin B tablets are all commonly used supplements. Hydroxocobalamin is a vitamin B12 injection given to people to prevent or treat certain types of anaemia. Folic acid is often used to prevent neural tube defects occurring during pregnancy.