Vitamin A

• Function: vision (retinal); reproduction/growth and maintenance of epithelial tissue (r. acid); can bind to receptors in nucleus to influence cell/neuronal development
• Pathway: eat B-carotene -> digest to retinol -> make retinal/retinoic acid
• Deficiencies: treat with retinol (if not: visual cells die/dry eye/corneal ulcer)
• Toxicity: enlarged liver; birth defects; peeling skin

Vitamin D

• Function: increase [Ca] binding protein so we can pull Ca from diet/activate osteoclasts when low [Ca]/can de-/acetylate histones
• Pathway: eat plants/animals to get it; sunlight catalyzes conversion of cholesterol derivative to previtamin
• Deficiency: rickets (soft bones in kids because it doesn't mineralize); osteomalacia (in adults)
• Toxicity: deposit Ca in arteries/kidneys

Vitamin E

(a-tocopherol)

• Function: antioxidant
• Pathway: vegetable oil, liver, eggs
• Deficiency: usually in premature babies: inadequate fat absorption/transport
• Toxicity: bleeding; hemorrhagic stroke

Vitamin K

• Function: allows prothrombin to bind Ca/post-translational mod of clotthing factors
• Pathway: K1 (from plants) / K2 (from bacteria)
• Deficiency: rare since Vit K is produced by intestinal bacteria; if deficient-> hypoprothrombinemia

Thiamine (B1)

• Active as thiamine pyrophosphate
• Function: involved in making pyruvate phosphatse (step before TCA) / is coenzyme in making/degrading a-ketol/oxidative decarboxylation of a-ketol
• Deficiency: Beri beri (in kids: tachycardia, vomiting, convulsions, death; in adults: dry skin, irritability, paralysis), Wernicke-Korsakoff (apathy, memory loss, ataxia -> due to alcoholism)

Riboflavin (B2)

• Active as FMN/FAD
• Function: detox/iron mobilization

Niacin (B3)

• Active as NAD+/NADP
• Function: coenzyme of redox rxns; DNA damage recognition/repair
• Deficiency: pellagra (3 D's: dermatitis, diarrhea, dementia)

Pantothenic acid

(B5)

• Function: component of coenzyme A (helps transfer acyl groups)
• Deficiency: fatigue, insomnia

Folic acid

(hematopoietic)

• Function: needed to make purines/serines/glycines
• Deficiencies: DNA synthesis is inhibited; RBC's are slow to mature and eventually burst

Cobalamin (B12)

(hematopoietic)

• Made in microorganisms/organized around Cobalt atom
• Deficiency: rare since has huge stores in body; if malnourished-> deficiency would cause pernicious anemia

Pyridoxine (B6)

• Function: forms pyridoxal phosphate (coenzyme for interconverting AA's into energy)
• Deficiency: sensory neuropathy (rare/relatively severe for a H2O-soluble vitamin)

Ascorbic Acid (Vit. C)

• Function: maintain CT; heal wounds; reduction/hydroxylation
• Deficiency: scurvy