Ingredient directory

The form of vitamin D the body makes from sunlight and the most effective supplemental form for raising blood levels.

Typical: 1,000–2,000 IU

Ascorbic acid is the reference form of vitamin C and the most common form in supplements; NIH ODS notes its bioavailability equals that of vitamin C naturally present in food.

Typical: 250–1,000 mg

Retinyl palmitate is an ester of retinol and the most common preformed vitamin A used in supplements and multivitamins.

Typical: 750–1,050 mcg

Chemically identical cholecalciferol extracted from lichen rather than sheep's wool lanolin, which lets a product carry vegan and vegetarian claims while keeping the D3 form that raises and holds serum 25(OH)D better than D2.

Typical: 1,000–2,000 IU

Sodium ascorbate is the sodium salt of ascorbic acid.

Typical: 250–1,000 mg

Beta-carotene is an orange plant pigment that the body can split into retinol as needed, which is why it is called provitamin A.

Typical: 3–15 mg

Ergocalciferol is the plant and fungal form of vitamin D, produced by UV irradiation of ergosterol from yeast or mushrooms.

Typical: 400–2,000 IU

Calcium ascorbate is the calcium salt of vitamin C, commonly supplied as the dihydrate.

Typical: 250–1,000 mg

Ascorbyl palmitate is an ester of ascorbic acid and palmitic acid that is soluble in fat rather than water.