Daily Vitamin Intake Calculator

The 13 Essential Vitamins

Humans require 13 essential vitamins to maintain health: 4 fat-soluble (A, D, E, K) and 9 water-soluble (C and the 8 B-complex vitamins). Each plays specific biochemical roles, from cofactor functions in metabolism to gene expression regulation.

Best Food Sources

• Vitamin A — liver, sweet potatoes, carrots, leafy greens
• Vitamin D — fatty fish, fortified milk, sunlight
• Vitamin E — nuts, seeds, vegetable oils
• Vitamin K — kale, spinach, natto
• B vitamins — whole grains, meat, eggs, leafy greens
• Vitamin C — citrus, peppers, broccoli, kiwi

Should You Take a Multivitamin?

A daily multivitamin is reasonable insurance if your diet is inconsistent. However, large randomized trials (Physicians' Health Study II, COSMOS) found only modest benefits for cancer prevention and none for cardiovascular disease. Food sources remain the gold standard because they deliver vitamins alongside fiber, phytochemicals and minerals in balanced ratios.