Fig. 2. Molecule structures of beta-carotene, vitamin D including lumisterol (D1), ergocalciferol (D2), cholecalciferol (D3), 22-dihydroergocalciferol (D4), and sitocalciferol (D5), and vitamin E congeners including tocopherols (α-tocopherol, β-tocopherol, γ-tocopherol, and δ-tocopherol) and tocotrienols (α-tocotrienol, β-tocotrienol, γ-tocotrienol, and δ-tocotrienol).
