Adults

Adults: 1-2 teaspoonfuls (5-10 ml) 2-3 times daily, or as directed by a physician.

Elderly

Elderly: Same as adult dosage, no specific adjustment usually required unless severe renal impairment is present for specific components.

Renal_impairment

No specific dosage adjustment is typically required for a general multivitamin B-complex. Consult a physician for high-dose formulations or severe impairment.

Onset

Effects on metabolic processes can begin shortly after absorption, but symptomatic improvement in deficiency states may take days to weeks.

Excretion

Primarily excreted unchanged or as metabolites in the urine. Renal clearance is the main route of elimination for most water-soluble B vitamins.

Half life

Varies significantly for each B vitamin; generally, they are water-soluble and not stored in large quantities, leading to relatively short half-lives (hours to days) and rapid excretion.

Absorption

Readily absorbed from the gastrointestinal tract, primarily in the small intestine. Absorption rates can vary depending on the specific vitamin and presence of other food components.

Metabolism

B vitamins are metabolized in the liver and various tissues to their active coenzyme forms. Excess amounts are typically not extensively metabolized.

Levodopa

High doses of Pyridoxine (Vitamin B6) may reduce the effectiveness of Levodopa (used in Parkinson's disease). This interaction is less significant with Carbidopa/Levodopa combinations.

Isoniazid

Can interfere with Pyridoxine metabolism, potentially requiring increased B6 supplementation.

Certain antibiotics (e.g., Cycloserine)

May increase the requirement for Pyridoxine.