cgoodell

• Fat soluble
• vision, growth and develop.(ameloblasts and odontoblasts, epithelial cell gene expression)
• cancer prevention-antioxidant

• toxicity-cell mem damage and birth defects (retin A)
• deficiency-blindness, neural tube degeneration, epi cell degeneration, enamel hypoplasia

muscle contraction, nerve impulse transmission, endoc. and exoc secretory responses, mem stability, blood clotting, intracellular messenger

intermediate in carb. lipid and prot metabolism ATP, creatine phos, cofactors NADP, second messengers-cAMP and IP3, DNA, RNA, phosphorylation of reg proteins