Study notes

Vitamin A activity: retinoids and provitamin A carotenoids

β-Carotene cleavage and measures of vitamin A activity

Vitamin A and the visual cycle

Retinoic acid receptors and interaction with vitamin D and thyroid hormone signaling

Vitamin A deficiency: visual progression and impaired immunity

Vitamin A toxicity: mechanism and organ manifestations

Vitamin D: endogenous synthesis, hormonal actions, and deficiency

Cutaneous synthesis and seasonal variation of vitamin D

Vitamin D hydroxylation in the liver and kidney

Calcitriol: feedback regulation and maintenance of plasma calcium

Potential benefits and source limitations of higher vitamin D intake

Skeletal effects of vitamin D deficiency

Vitamin D excess and protection against sunlight-induced toxicity

Vitamin E: membrane functions, vitamer families, and potency

Vitamin E antioxidant action and regeneration by vitamin C

Vitamin E deficiency: impaired absorption and membrane injury

Vitamin K: dietary forms, bacterial sources, and antagonists

Vitamin K-dependent carboxylation and the effect of warfarin

γ-Carboxyglutamate in blood-clotting proteins

Vitamin K–dependent calcium-binding proteins outside coagulation

Thiamin coenzymes in metabolism and nerve conduction

Thiamin deficiency: neurological, cardiac, and metabolic effects

Assessment of thiamin status by erythrocyte transketolase activation

Riboflavin: coenzymes, synthesis and dietary sources

Flavin coenzymes in oxidoreduction and oxidant stress

Riboflavin deficiency: conservation, manifestations, and assessment

Niacin: synthesis, active forms, and metabolic function

NAD-derived ADP-ribose in DNA repair and calcium signaling

Pellagra: nutritional basis and clinical progression

Pellagra despite adequate tryptophan and niacin intake

Adverse effects of excessive niacin intake

Vitamin B6: coenzyme forms, metabolic roles, and deficiency

Vitamin B6 assessment and toxicity; vitamin B12 sources and initial absorption

Vitamin B12 absorption, dependent enzymes, and deficiency

Pernicious anemia: intrinsic factor failure and spinal cord degeneration

Dietary folate forms and dietary folate equivalents

Tetrahydrofolate carriage of one-carbon units

Folate metabolism in DNA synthesis and drug action

Vitamin B12 deficiency and the folate trap

Folate deficiency and megaloblastic anemia