Vitamins and their deficiencies Flashcards
(30 cards)
Vitamin A - Name and Function
Retinol
- Antioxidant
- Visual pigment component
- epithelial specialization (prevents squamous metaplasia)
Vitamin A Deficiency - S/S (5)
- Night blindness (nyctalopia)
- Dry, scaly skin
- Corneal degeneration
- Bitot spots on conjunctiva
- Immunosuppression
Vitamin A Toxicity (Acute, Chronic, Teratogenic)
Acute: N/V, vertigo, blurred vision
Chronic: Alopecia, dry scaly skin, hepatomegaly, arthralgia, pseudotumor cerebri (↑ICP)
Teratogenic: cleft palate + cardiac abnormalities
Vitamin B1 - Name and Function
Thiamine = dehydrogenase (dh) cofactor for:
- pyruvate dh (glycolysis/TCA link)
- α-ketoglutarate dh (TCA cycle)
- transketolase (HMP shunt)
- branched-chain ketoacid dh
Vitamin B1 Deficiency - S/S (general) and Dx
Impaired glucose metabolism => ATP depletion worsened by glucose infusion (brain, heart affected first)
Dx w/ ↑ RBC transketolase activity upon repletion
Wernicke-Korsakoff Syndrome - Cause + S/S (classic 3 + some)
B1 (Thiamine) deficiency (malnutrition, EtOHism)
- confusion
- opthalmoplegia (extraoccular muscle weakness/paralysis)
- ataxia
- confabulation, personality change, permanent memory loss
Wernicke-Korsakoff Syndrome - which part of brain?
- medial dorsal nucleus (thalamus)
- mammillary bodies
Beriberi - Cause and S/S (2+2)
B1 (Thiamine) deficiency (malnutrition, EtOHism)
Dry: polyneuritis, symmetrical muscle wasting
Wet: high-output cardiac failure (dilated CM), edema
Vitamin B2 - Name and Function
Riboflavin
component of FAD and FMN (redox reaction cofactors)
Vitamin B2 Deficiency - S/S (2)
Cheilosis (lip inflammation + scaling/fissures @ mouth corners)
Corneal vascularization
Vitamin B3 - Name and Function
Niacin
component of NAD+ and NADP+
Vitamin B3 - Derived from what?
Tryptophan with B2 + B6 required for synthesis
Vitamin B3 - Used medically for…
dyslipidemia (↑HDL and ↓VLDL)
Vitamin B3 Deficiency - Causes
Hartnum Dz = impaired tryptophan absorption
Malignant carcinoid syndrome (↑ tryptophan metabolism)
Isoniazid (↓B6)
Pellagra - Cause + S/S (5)
Severe B3 (niacin) deficiency
- glossitis
- Diarrhea
- Dementia/hallucinations
- Dermatitis (C3/C4 dermatome = “broad collar” or “Casal necklace”)
- hyperpigmentation of sun-exposed limbs
Vitamin B3 Excess - S/S (3)
- flushing (PG, no histamine => aspirin prevents)
- hyperglycemia
- hyperuricemia
Vitamin B5 - Name + Function
Pantothenic Acid
-Component of CoA and fatty acid synthase
Vitamin B5 deficiency S/S (4)
- Allopecia
- Adrenal insufficiency
- Dermatitis
- Enteritis
Vitamin B6 - Name + Function
Pyridoxine
- Converted to PLP, a transamination, decarboxylation, and glycogen phosphorylase cofactor
- Synthesis of: cystathionine, heme, niacin, and neurotransmitter
Vitamin B6 Deficiency - S/S (4)
- Irritability
- Sideroblastic anemia (impaired heme synthesis + Fe excess)
- Convulsions
- Peripheral neuropathy
Vitamin B6 Deficiency - Cause
Isoniazid and OCP’s
Vitamin B9 - Name and Function
Folate
-Converted to THF = coenzyme for methyl transfer rxn’s (nitrogenous base synthesis for RNA/DNA)
Folate absorbed in the…
Jejunum
Vitamin B9 Deficiency - S/S (3)
- Macrocytic anemia
- Hypersegmented PMN’s
- Glossitis
