The long-term ingestion of certain drugs may imbalance the vitamin equilibrium as they can influence uptake, utilization, storage, and excretion rate of vitamins in the body. Oral contraceptives (the ‘pill’), for example, may affect the need for vitamin B6 and vitamin B9 (folic acid). Diuretics can increase the excretion of some vitamins with urine, which increases the demand. Other drugs that can intervene in the vitamin balance are, for example, certain antibiotics and sulfonamides, anti-malaria drugs and anti-tuberculosis cure. In some cases, the ‘anti-vitamin effect’ is used in disease treatment, for example in cancer chemotherapy.