Water soluble vitamins deficiency Notes

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Osmosis High-Yield Notes

This Osmosis High-Yield Note provides an overview of Water soluble vitamins deficiency essentials. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find more information about Water soluble vitamins deficiency by visiting the associated Learn Page.
NOTES NOTES WATER SOLUBLE VITAMINS DEFICIENCY GENERALLY, WHAT IS IT? PATHOLOGY & CAUSES ▪ Vitamin: micronutrient that participates in essential cellular function SIGNS & SYMPTOMS ▪ See individual disorders DIAGNOSIS CAUSES ▪ Insufficient water-soluble vitamin intake → ↑ demand, malabsorption, loss → insufficient for body’s metabolic needs COMPLICATIONS ▪ Chronic water-soluble vitamin deficiency → specific clinical disorders OTHER DIAGNOSTICS ▪ History, clinical presentation TREATMENT OTHER INTERVENTIONS ▪ ↑ dietary intake ▪ Synthetic formulation supplementation ▪ Address complications FOLATE (VITAMIN B9) DEFICIENCY osms.it/folate-(vitamin-b9)-deficiency PATHOLOGY & CAUSES ▪ Insufficient folate (pteroylglutamic acid) for body’s metabolic needs ▪ Body cannot synthesize, normally maintains low stores ▪ Folate must be obtained in diet; lack for several weeks → deficiency ▪ Folate deficiency → impaired DNA synthesis during erythropoiesis (cell cycle S-phase delay) → uncoordinated cytoplasm, nuclei maturation in erythroblasts (nuclear-cytoplasmic asynchrony) → ineffective hematopoiesis → ↑ erythroid apoptosis + abnormally large erythrocytes (macrocytosis) → defective cells with fragile membranes → ↓ red blood cell (RBC) lifespan → anemia Sources of folate ▪ Present naturally in plant (especially dark green leafy vegetables), animal products (especially liver) ▪ Folic acid available in dietary supplements, fortified foods (e.g. cereals) Recommended dietary allowances (RDAs) ▪ Folate RDAs listed as micrograms of dietary folate equivalents (DFEs), reflect OSMOSIS.ORG 301
▪ ▪ ▪ ▪ higher bioavailability in food vs. supplement Child 9–13: 300mcg DFE 14+: 400mcg DFE Pregnancy: 600mcg Lactation: 500mcg RISK FACTORS Insufficient diet ▪ Alcohol abuse ▫ Impairs folate absorption, metabolism; accelerates breakdown ▪ Chronic systemic disease; mental illness; advanced age ▪ Food insecurity ▪ Self-imposed dietary restrictions (e.g. vegan) ▪ ↓ vitamin C (cofactor for folate metabolism) Adequate diet but increased requirements ▪ Pregnancy, lactation, malignancy ▪ Disease state with ↑ cellular turnover (e.g. chronic hemolysis, exfoliative skin disease) Malabsorption ▪ E.g. celiac disease, inflammatory bowel disease, gastric surgery, achlorhydria Metabolic interference from medication ▪ E.g. methotrexate (folate antagonist), phenytoin, trimethoprim Hereditary forms ▪ Hereditary folate malabsorption (HFM) ▫ Loss-of-function mutation of PFCT gene encoding for proton-coupled folate transporter (rare, autosomal recessive disorder) ▪ Infantile cerebral folate deficiency ▫ Autoantibody against folate receptor in choroid plexus → prevents folate transport across blood-brain barrier COMPLICATIONS ▪ Megaloblastic anemia ▪ Insufficient folate during gestation → ↑ neural tube defect risk ▪ Developmental delay, neurological disorders (child) 302 OSMOSIS.ORG SIGNS & SYMPTOMS ▪ Megaloblastic anemia ▫ Hypoxemia, tissue hypoxia → fatigue, activity intolerance, pallor, ↑ heart rate ▪ ↑ hemolysis → jaundice ▪ Atrophic glossitis, angular stomatitis, anorexia, nausea, diarrhea ▪ Hereditary folate malabsorption ▫ Manifests at age 1–3 months ▫ Failure to thrive, neurologic deterioration, megaloblastic anemia ▪ Infantile cerebral folate deficiency ▫ Manifests at age 4–6 months ▫ Irritability, ↓ sensorineural hearing, seizure, developmental delay, sleep disturbance → visual disturbance/loss DIAGNOSIS LAB RESULTS ▪ ↓ RBC count; ↓ reticulocyte count; evidence of megaloblastic anemia (↑ mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH)) ▪ Macrocytosis, anisocytosis, poikilocytosis, hypersegmented neutrophils ▪ ↑ hemolysis markers ▫ ↓ indirect bilirubin, ↓ lactate dehydrogenase, ↓ haptoglobin ▪ ↓ serum folate ▪ Hypercellular bone marrow ▪ Infantile cerebral folate deficiency ▫ Cerebrospinal fluid (CSF) assay shows ↓ 5-methyltetrahydrofolate ▫ Serum, RBC folate normal TREATMENT OTHER INTERVENTIONS ▪ Address complications (e.g. neurologic manifestation) ▪ ↑ dietary folate intake ▪ Folic acid supplementation (synthetic formulation)
Chapter 53 Water Soluble Vitamins Deficiency NIACIN (VITAMIN B3) DEFICIENCY osms.it/niacin-(vitamin-b3)-deficiency PATHOLOGY & CAUSES ▪ Insufficient niacin (nicotinic acid, nicotinamide) for body’s metabolic needs ▫ Niacin obtained in diet ▫ Liver converts tryptophan to niacin (60g tryptophan = 1mg niacin) ▪ Active forms ▫ Nicotinamide adenine dinucleotide (NAD+), nicotinamide adenine dinucleotide phosphate (NADP+) ▪ Moderate/↑ doses of niacin supplement → ↓ total/low-density lipoprotein (LDL) cholesterol Sources of niacin ▪ Present in plant, animal products (e.g. dairy products, meat, grain (↓ corn), legumes, seeds) ▪ Dietary supplement; enriched grain, cereal, milk Metabolic defects ▪ E.g. carcinoid syndrome → impaired tryptophan metabolism Accelerated niacin depletion ▪ Prolonged isoniazid use → ↓ pyridoxal phosphate (active form of vitamin B6) → ↑ tryptophan synthesis Tryptophan-to-niacin conversion nhibited by medication ▪ E.g. phenobarbital, chloramphenicol, pyrazinamide COMPLICATIONS ▪ Pellagra RDAs ▪ Children 9–13: 12mg ▪ 19+ male: 16mg; 19+ female: 14mg ▪ Pregnancy: 18mg ▪ Lactation: 14mg RISK FACTORS Insufficient niacin/tryptophan intake ▪ Alcohol abuse ▪ Self-imposed dietary restrictions ▪ Chronic systemic disease; mental illness; advanced age ▪ Food insecurity ▪ Corn-based diet (unless corn treated with alkali, e.g. tortillas) Malabsorption ▪ E.g. bariatric surgery, malabsorptive disease states ▪ Hartnup disorder: defective tryptophan absorption Figure 53.1 A desqauamating rash on the skin of an individual who presented with diarrhea and confusion. The diagnosis was confirmed as pellagra. OSMOSIS.ORG 303
SIGNS & SYMPTOMS ▪ Dermatitis ▫ Photosensitive, pigmented ▪ Diarrhea ▫ Potentially also vomiting ▪ Dementia ▫ Potentially also anxiety, disorientation ▪ Death ▫ Untreated pellagra potentially fatal DIAGNOSIS LAB RESULTS ▪ ↓ N-methylnicotinamide (niacin metabolism product) TREATMENT OTHER INTERVENTIONS ▪ Niacin supplementation ▪ ↑ dietary niacin/tryptophan ▪ Address complications VITAMIN B12 DEFICIENCY osms.it/vitamin-b12-deficiency PATHOLOGY & CAUSES ▪ Insufficient B12 for body’s metabolic needs ▪ Active cobalamin (coenzyme) forms: methylcobalamin, 5-deoxyadenosylcobalamin ▪ Dietary cobalamin in food protein → gastric hydrochloric acid, protease-free cobalamin → cobalamin + intrinsic factor complex → distal ileum absorption ▪ Cobalamin essential for metabolic reactions involving hematopoiesis; protein, DNA, RNA, myelin synthesis; gastrointestinal tract mucosa maintenance ▫ Methylcobalamin: methionine synthase (folate-dependent enzyme) cofactor → methionine synthase catalyzes homocysteine remethylation to form methionine (essential amino acid for tissue growth/repair; hormone, protein, purine, pyrimidine synthesis) ▫ 5-deoxyadenosylcobalamin: L-methylmalonyl-coenzyme A conversion to succinyl CoA → enters citric acid cycle → lipid, protein energy production ▪ Impaired DNA synthesis during erythropoiesis (e.g. cell cycle S-phase delay) → uncoordinated cytoplasm, 304 OSMOSIS.ORG nuclei maturation in erythroblasts (nuclear-cytoplasmic asynchrony) → ineffective hematopoiesis → ↑ erythroid apoptosis, abnormally large erythrocytes (macrocytosis) → defective cells with fragile membranes → ↓ RBC lifespan → anemia Sources of cobalamin ▪ Animal products (meat, egg, dairy) ▪ Supplements, enriched food RDAs ▪ Child 9–13: 1.8mcg ▪ 14+: 2.4mcg RISK FACTORS Insufficient intrinsic factor ▪ Pernicious anemia ▫ Autoimmune condition destroys parietal cells → ↓ intrinsic factor production → cobalamin not absorbed ▪ Gastrectomy, bariatric surgery ▪ Gastric atrophy Malabsorption ▪ Achlorhydria (acid promotes gastric mucosa absorption) ▫ ↑ age → ↑ risk ▫ ↓ acid due to medication (e.g. antacid,
Chapter 53 Water Soluble Vitamins Deficiency H2 receptor blocker, proton pump inhibitor) ▫ Ileal resection, disease (e.g. celiac disease) Insufficient diet ▪ Alcohol abuse ▪ Chronic systemic disease, mental illness, advanced age ▪ Food insecurity ▪ Self-imposed dietary restrictions (e.g. vegan) Adequate diet but increased requirements ▪ Pregnancy, lactation, malignancies ▪ Disease states with ↑ cellular turnover (e.g. chronic hemolysis, exfoliative skin disease) Medication interfering with absorption ▪ E.g. Metformin, cycloserine, isoniazid, neomycin Fish tapeworm Diphyllobothrium latum infestation ▪ Competes for absorption in ileum Imerslund–Gräsbeck syndrome ( juvenile megaloblastic anemia) ▪ Autosomal recessive disorder ▪ Vitamin B12-intrinsic factor receptor defect cblD inborn error of cobalamin metabolism ▪ MMADHC gene mutation → MMADHC protein defect (cobalamin transporter) COMPLICATIONS ▪ Macrocytic anemia ▪ Neurodegenerative disorder ▪ ↑ hemolysis → jaundice ▪ ↓ gastrointestinal tract mucosa integrity → atrophic glossitis, angular stomatitis, anorexia, nausea, diarrhea ▪ Impaired myelin production → cognitive impairment, paresthesias, impaired proprioception, gait disturbance, slowed cognition DIAGNOSIS LAB RESULTS Blood study ▪ ↓ cobalamin ▪ CBC ▫ ↓ RBC count; ↓ reticulocyte count; megaloblastic anemia (↑ MCV, ↓ MCH) ▪ Blood smear analysis ▫ Macrocytosis, oval macrocytes; anisocytosis; poikilocytosis; hypersegmented neutrophils ▪ ↑ hemolysis markers ▫ Elevated indirect bilirubin, lactate dehydrogenase, ↓ haptoglobin Hypercellular bone marrow TREATMENT OTHER INTERVENTIONS ▪ ↑ dietary cobalamin ▪ Supplementation (cyanocobalamin) ▫ Pernicious anemia → parenteral cobalamin ▪ Address complications SIGNS & SYMPTOMS ▪ High body stores → 1–2 years insufficient intake → symptoms (adult/child) ▪ B12-deficient mothers → infant cobalamin deficiency sequelae at age 6–18 months ▪ Megaloblastic anemia ▫ Hypoxemia, tissue hypoxia → fatigue, activity intolerance, pallor, ↑ heart rate OSMOSIS.ORG 305
VITAMIN C DEFICIENCY osms.it/vitamin-c-deficiency PATHOLOGY & CAUSES SIGNS & SYMPTOMS ▪ Insufficient vitamin C for body’s metabolic needs ▪ Body cannot synthesize, must obtain in diet ▪ Active form: L-ascorbic acid ▪ ↓/no intake → symptoms within one month ▪ Mucocutaneous signs ▫ Spongy gums → loose teeth ▫ Capillary fragility → petechiae, ecchymoses, perifollicular hemorrhage, subperiosteal hemorrhage ▫ Hair structure changes → corkscrew hair ▪ Inability to maintain bone matrix ▫ Arthralgias, bone structure changes ▪ Anemia ▫ Fatigue, malaise ▪ Impaired wound healing RDA ▪ 9–13 years old: 45mg ▪ 14–18 years old: 75 mg (biologically-male); 65mg (biologically-female) ▪ 19+ years old: 90 mg (biologically-male); 75mg (biologically-female) ▪ Pregnancy: 85mg ▪ Lactation: 120mg ▪ Smokers: ↑ 35mg/day RISK FACTORS Insufficient diet ▪ Food insecurity ▪ Self-imposed dietary restrictions ▪ Chronic systemic disease, mental illness, advanced age ▪ Feeding infants evaporated/boiled cow’s milk ↑ oxidative stress ▪ Smoking, secondhand smoke COMPLICATIONS ▪ Scurvy, related sequelae (e.g. periodontal disease; bone, joint disorders) ▪ Impaired wound healing ▪ Weakened immune system ▪ Depression ▪ Microcytic anemia 306 OSMOSIS.ORG DIAGNOSIS DIAGNOSTIC IMAGING MRI ▪ Sclerotic, lucent metaphyseal bands, soft tissue edema TREATMENT OTHER INTERVENTIONS ▪ ↑ dietary/supplementation vitamin C ▫ Present in many fruits, vegetables (especially citrus, tomatoes, broccoli, bell peppers, potatoes) ▫ Supplements, enriched grains ▪ Address complications
Chapter 53 Water Soluble Vitamins Deficiency Figure 53.2 An X-ray of the leg of a child with scurvy. There is a dense zone of provisional calcification at the epiphysis, known as a Frankel line, with underlying radiolucency known as a Trümmerfeld zone. OSMOSIS.ORG 307

Osmosis High-Yield Notes

This Osmosis High-Yield Note provides an overview of Water soluble vitamins deficiency essentials. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find more information about Water soluble vitamins deficiency by visiting the associated Learn Page.