Vitamins and micronutrients

Thiamine active coenzyme form

Thiamine pyrophosphate (TPP)

Thiamine function

Oxidative decarboxylation of pyruvate and α‑ketoglutarate; transketolase reactions

Thiamine deficiency syndrome

Beriberi

Adult beriberi types

Dry (neuropathy) and Wet (cardiac edema)

Infantile beriberi cause

Breastfed infants of thiamine‑deficient mothers

Riboflavin active forms

FMN and FAD

Riboflavin function

Coenzymes in oxidation‑reduction reactions

Riboflavin deficiency signs

Dermatitis, cheilosis, glossitis

Niacin active forms

NAD and NADP

Niacin function

Coenzymes in redox reactions

Niacin deficiency disease

Pellagra

Pellagra classic triad

Dermatitis, Diarrhea, Dementia (→ Death if untreated)

Niacin sources

Grains, milk, lean meats, liver

Pantothenate function

Component of CoA and acyl carrier protein of fatty acid synthase

Pantothenate sources

Eggs, liver, yeast

Pantothenate deficiency signs

Dermatitis, alopecia, adrenal insufficiency

Pyridoxine collective term

Pyridoxine, pyridoxal, pyridoxamine

Pyridoxine active coenzyme

Pyridoxal phosphate (PLP)

Pyridoxine function

Amino acid metabolism enzymes

Drug causing B6 deficiency

Isoniazid (forms inactive derivative with PLP)

Pyridoxine deficiency signs

Angular cheilosis, glossitis, convulsions, neuropathy

Unique toxicity of B6

Sensory neuropathy at >500 mg/day

Biotin function

Coenzyme in carboxylation reactions

Biotin deficiency symptoms

Dermatitis, glossitis, loss of appetite, nausea

Biotin source

Widely distributed in food + intestinal bacteria

Folate function

One‑carbon metabolism; purine and TMP synthesis

Folate deficiency common groups

Pregnant women, alcoholics

Folate deficiency anemia type

Megaloblastic anemia

Folate deficiency in pregnancy

Neural tube defects (spina bifida, anencephaly)

Folate supplementation recommendation

0.4 mg/day for women of childbearing age

Vitamin B12 functions

Homocysteine → methionine; methylmalonyl CoA isomerization

Vitamin B12 sources

Animal products only (liver, meat, fish, eggs, dairy)

Vitamin B12 storage

2–5 mg in body

Vitamin B12 absorption site

Terminal ileum (requires intrinsic factor)

Vitamin B12 deficiency causes

Malabsorption in elderly, pernicious anemia (autoimmune destruction of parietal cells)

Vitamin B12 deficiency manifestations

Megaloblastic anemia + neurologic symptoms

Vitamin C functions

Collagen hydroxylation, iron absorption, antioxidant

Vitamin C deficiency disease

Scurvy

Scurvy signs

Sore gums, loose teeth, hemorrhage, swollen joints, fatigue, poor wound healing, microcytic anemia

Vitamin A functions

Vision, reproduction, growth, epithelial maintenance, immunity

Vitamin A forms

Retinol, Retinal, Retinoic acid, β‑carotene

Vitamin A sources

Liver, kidney, butter, egg yolk; carotene in vegetables/fruits

Vitamin A deficiency early sign

Night blindness

Vitamin A deficiency severe

Xerophthalmia, corneal ulceration, keratinization, blindness

Vitamin A toxicity

Hypervitaminosis A → teratogenic birth defects

Vitamin D active form

1,25‑dihydroxycholecalciferol (Calcitriol)

Vitamin D sources

Sunlight (D3), diet (D2 plants, D3 animal tissue)

Vitamin D functions

Regulates Ca and P (↑ intestinal absorption, ↑ renal reabsorption, ↑ bone resorption)

Vitamin D deficiency diseases

Rickets in children, osteomalacia in adults

Vitamin D toxicity

Hypercalcemia, calcium deposition in organs

Vitamin E most active form

α‑Tocopherol

Vitamin E function

Antioxidant preventing lipid peroxidation

Vitamin E sources

Vegetable oils, liver, eggs

Vitamin E deficiency risk

Premature infants, adults with lipid absorption defects

Vitamin K forms

K1 (phylloquinone), K2 (menaquinone), synthetic K3 (menadione)

Vitamin K function

Coenzyme for clotting factors II, VII, IX, X; proteins C & S

Vitamin K sources

Green leafy vegetables, egg yolk, liver, gut bacteria

Vitamin K deficiency risk

Newborns (sterile gut, low milk vitamin K)

Vitamin K prophylaxis in newborns

Single IM dose to prevent hemorrhagic disease

Sodium location

Most abundant extracellular cation

Potassium location

Most abundant intracellular cation

Na/K functions

Regulate osmotic pressure, maintain membrane potential for nerves and muscles

Na/K depletion causes

Perspiration, vomiting, diarrhea, diuretics, excess ADH

Calcium functions

Bones/teeth, nerve impulses, muscle contraction, blood coagulation, intracellular signaling

Calcium regulation

Calcitonin, calcitriol, parathyroid hormone

Calcium deficiency causes

Vitamin D deficiency, hypomagnesemia, hypoalbuminemia, poor diet

Calcium deficiency signs

Paraesthesia, cramps, fractures, tetany in alkalosis

Phosphate location

Most abundant intracellular anion

Phosphate functions

Counter‑ion to Ca in mineralization, ATP functional group, blood buffer

Phosphate depletion cause

Alkalosis

Magnesium functions

Bone structure, nerve transmission, muscle contraction, Ca regulation, enzyme cofactor (ATPase)

Magnesium depletion causes

Diuretics, alcoholism

Magnesium deficiency signs

Neuromuscular excitability, paraesthesia

Chloride location

Most abundant extracellular anion

Chloride functions

Fluid/electrolyte balance, gastric fluid

Chloride deficiency cause

Secondary to vomiting/diarrhea

Iron transport protein

Transferrin (binds 2 iron molecules)

Iron storage forms

Ferritin, hemosiderin

Iron deficiency causes

Inadequate intake, chronic occult bleeding, excessive menstruation

Earliest sign of iron deficiency

Anemia

Iron excess condition

Hemosiderosis/hemochromatosis

Zinc functions

Cofactor for metalloenzymes (SOD, collagenase, ADH); spermatogenesis, growth

Zinc deficiency causes

Poor intake, alcoholism, chronic diarrhea, inflammation

Zinc deficiency signs

Poor wound healing, hypogonadism, growth impairment

Copper functions

Cofactor for oxidases (ceruloplasmin, tyrosinase, cytochrome oxidase)

Copper transport protein

Ceruloplasmin

Copper deficiency cause

Total parenteral nutrition

Copper excess disease

Wilson disease (neurologic symptoms, lens deposits)

Chromium function

Glucose tolerance factor; works with insulin

Chromium sources

Cheese, grains, nuts, yeast

Chromium deficiency

Impaired glucose tolerance

Iodine function

Thyroid hormone synthesis

Iodine sources

Iodised salt, seafood

Iodine deficiency

Goitre, thyrotoxicosis

Manganese function

Cofactor esp. superoxide dismutase

Manganese sources

Plant foods, tea

Manganese deficiency

Unknown

Selenium function

Glutathione peroxidase (selenoproteins)

Selenium sources

Liver

Selenium deficiency

↓ glutathione peroxidase, Keshan disease