Code of Federal Regulations Title 21. Food and Drugs § 21.184.1950 Vitamin D

(1) Crystalline vitamin D₂ (C₂₈H₄₄O, CAS Reg. No. 50–14–6), also known as ergocalciferol, is the chemical 9,10–seco(5Z,7E,22E)–5,7,10(19),22–ergostatetraen–3–ol. The ingredient is produced by ultraviolet irradiation of ergosterol isolated from yeast and related fungi and is purified by crystallization.

(2) Crystalline vitamin D₃ (C₂₇H₄₄O, CAS Reg. No. 67–97–0), also known as cholecalciferol, is the chemical 9,10–seco(5Z,7E,)–5,7,10(19)-cholestatrien–3–ol. Vitamin D₃ occurs in, and is isolated from, fish liver oils. It is also manufactured by ultraviolet irradiation of 7–dehydrocholesterol produced from cholesterol. It is purified by crystallization. Vitamin D₃ is the vitamin D form that is produced endogenously in humans through sunlight activation of 7–dehydrocholesterol in the skin.

(3) Vitamin D₂ resin and vitamin D₃ resin are the concentrated forms of irradiated ergosterol (D₂) and irradiated 7–dehydrocholesterol (D₃) that are separated from the reacting materials in paragraphs (a) (1) and (2) of this section. The resulting products are sold as food sources of vitamin D without further purification.

(c)(1) In accordance with § 184.1(b)(2), the ingredients are used in food as the sole source of added vitamin D only within the following specific limitations:

(2) Vitamin D may be used in infant formula in accordance with section 412(g) of the Federal Food, Drug, and Cosmetic Act (the act) or with regulations promulgated under section 412(a)(2) of the act.

(3) Vitamin D may be used in margarine in accordance with § 166.110 of this chapter.