Water/Fat Soluble Vitamins

|

Water soluble vitamins are provided at levels greater than the RDA since rapid administration exceeds renal threshold and therefore increases urinary losses. Fat soluble vitamins can become toxic, and are provided in amounts equal to the RDA, except for Vitamin K. Vitamin K is not provided because it may interfere with anticoagulant medications. Vitamin K must be given parenterally or intramuscularly, at a dose of 2-4 mg/wk, depending on prothrombin time. A long prothrombin time indicates an increased vitamin K need.

Excess water soluble vitamins can be easily excreted by the kidneys.