Adults

One tablet daily, preferably with a meal, or as directed by a physician.

Elderly

One tablet daily, or as directed by a physician. No specific dose adjustment is usually required.

Renal_impairment

Use with caution and consult a physician, especially if severe impairment. Dose adjustment may be necessary for some minerals.

Onset

Gradual; benefits typically seen after consistent use for several weeks.

Excretion

Water-soluble vitamins and excess minerals are primarily excreted via urine. Fat-soluble vitamins and some minerals are eliminated through bile and feces.

Half life

Highly variable depending on the specific vitamin/mineral and body's storage capacity (e.g., water-soluble vitamins have short half-lives, fat-soluble vitamins are stored longer).

Absorption

Vitamins and minerals are absorbed primarily in the small intestine through various active and passive transport mechanisms. Bioavailability varies for each component.

Metabolism

Water-soluble vitamins are generally not metabolized extensively and are excreted. Fat-soluble vitamins are metabolized by the liver. Minerals are regulated by homeostatic mechanisms.

Antacids

May decrease the absorption of iron and some other minerals.

Warfarin

Vitamin K (if present in significant amounts) may interfere with warfarin's anticoagulant effect (usually minimal in typical multivitamin doses).

Levothyroxine

Calcium and iron may interfere with levothyroxine absorption. Take several hours apart.

Tetracyclines/Quinolones

Minerals like calcium, iron, and zinc can interfere with the absorption of these antibiotics. Take at least 2 hours apart.