After reading this note you will be able to recognise, investigate and initiate appropriate management of common nutritional and vitamin deficiency states seen in Kenyan clinical rotations, while knowing where to verify doses and local protocols in the Kenya MoH guideline and your hospital formulary.
Definition
Nutrition and vitamin deficiencies refer to states in which intake, absorption, transport, storage or utilisation of macronutrients (protein, carbohydrate, fat) or micronutrients (vitamins, minerals) is insufficient to meet the body’s metabolic demands, leading to clinical signs, biochemical abnormalities and functional impairment.
Anatomy and physiology you need
| System | Key structures/functions relevant to nutrition |
|---|---|
| Gastro‑intestinal tract | Oral cavity, stomach acid, pancreatic enzymes, brush‑border transporters, ileal bile acid re‑absorption |
| Liver | Synthesis of transport proteins (e.g., RBP, transcobalamin), storage of fat‑soluble vitamins, gluconeogenesis |
| Pancreas | Exocrine enzymes for fat digestion, endocrine insulin/glucagon for carbohydrate utilisation |
| Kidneys | Re‑absorption of water‑soluble vitamins, activation of vitamin D |
| Bone marrow & muscle | Sites of protein synthesis, iron incorporation, vitamin‑dependent enzymatic reactions |
| Immune system | Lymphocyte proliferation, oxidative burst (vitamin C, E), cytokine modulation (vitamin D) |
Causes and risk factors
- Inadequate dietary intake – poverty, food insecurity, restrictive diets, alcoholism.
- Malabsorption – chronic diarrhoea (TB, HIV enteropathy, malaria), celiac disease, pancreatic insufficiency, post‑surgical resections.
- Increased requirements – pregnancy, lactation, severe infection (TB, HIV, malaria), burns, sickle‑cell crises.
- Losses – chronic vomiting, diarrhoea, dialysis, haemodialysis, extensive wounds.
- Drug‑induced – anticonvulsants (vitamin D), isoniazid (vitamin B6), antiretrovirals (folate).
- Chronic diseases – HIV/AIDS, pulmonary TB, malaria, rheumatic fever (inflammation‑driven catabolism), sickle‑cell disease (hemolysis → folate loss).
- Socio‑economic & environmental – rural subsistence farming, limited access to fortified foods, seasonal famines.
Pathophysiology
Protein‑energy malnutrition → inadequate amino acids → ↓ synthesis of transport proteins & immune mediators → muscle wasting, oedema, impaired immunity.
Vitamin A deficiency → ↓ retinal pigment & mucosal integrity → keratinisation of conjunctiva → night blindness, xerophthalmia.
Thiamine (B1) deficiency → ↓ pyruvate dehydrogenase activity → accumulation of lactate → beriberi (wet → high‑output cardiac failure; dry → peripheral neuropathy).
Riboflavin (B2) deficiency → ↓ flavoprotein co‑enzymes → impaired fatty‑acid oxidation → cheilosis, glossitis.
Niacin (B3) deficiency → ↓ NAD/NADP → impaired oxidative metabolism → pellagra (dermatitis, diarrhoea, dementia).
Pyridoxine (B6) deficiency → ↓ aminotransferases & neurotransmitter synthesis → peripheral neuropathy, sideroblastic anaemia.
Folate & Vitamin B12 deficiency → ↓ DNA synthesis in rapidly dividing cells → megaloblastic anaemia, glossitis, neuro‑psychiatric changes (B12).
Vitamin C deficiency → ↓ collagen hydroxylation → fragile capillaries → petechiae, poor wound healing, scurvy.
Vitamin D deficiency → ↓ calcium‑phosphate absorption → secondary hyperparathyroidism → osteomalacia, rickets.
Vitamin E deficiency → ↓ antioxidant protection of membranes → hemolytic anaemia, neuropathy (rare, seen in fat‑malabsorption).
Mineral deficiencies (iron, iodine, zinc) follow similar patterns of impaired synthesis or hormone production.
The above causal arrows illustrate how a primary nutritional insult translates into the characteristic clinical picture.
Clinical features
| Aspect | Questions to ask | Why it matters |
|---|---|---|
| General | Weight trend (loss, gain, plateau); appetite changes; dietary intake (type, frequency, food security); recent illness or hospitalisation; socioeconomic factors; alcohol or substance use | Weight loss or poor intake is the first clue to malnutrition; socioeconomic constraints are common drivers in Kenya. |
| Gastro‑intestinal | Nausea, vomiting, diarrhoea, constipation, dysphagia, odynophagia, abdominal pain, bloating, recent bariatric surgery or intestinal resection | Chronic diarrhoea or malabsorption syndromes (e.g., tropical sprue, HIV enteropathy) directly reduce nutrient absorption. |
| Metabolic / Endocrine | Polyuria, polydipsia, heat intolerance, cold intolerance, menstrual irregularities, libido changes, fatigue, muscle weakness | Thyroid disorders, diabetes and adrenal insufficiency can mimic or aggravate nutritional deficits. |
| Specific vitamin‑related | Night‑time visual disturbances, peripheral neuropathy, paresthesias, muscle cramps, easy bruising, gum bleeding, hair loss, skin changes (hyperpigmentation, scaling), oral ulcerations, sore tongue, poor wound healing | Classic manifestations of deficiencies (e.g., vitamin A – night blindness; B‑complex – neuropathy; C – gum disease; D – bone pain). |
| Infection‑related | HIV status, TB treatment history, malaria episodes, recurrent infections, sickle‑cell crises, rheumatic fever episodes | Chronic infections increase catabolism and nutrient loss; some (e.g., TB) cause specific micronutrient depletion. |
| Medication history | Use of antiretrovirals, anti‑TB drugs, anticonvulsants, diuretics, steroids, metformin, oral contraceptives | Certain drugs interfere with absorption or increase excretion of vitamins (e.g., isoniazid → B6 depletion). |
| Functional | Ability to perform ADLs, exercise tolerance, school/work attendance | Functional decline often precedes overt biochemical abnormalities. |
Examination findings and rationale
| Finding | What it indicates | Pathophysiologic link |
|---|---|---|
| Weight loss / low BMI | Undernutrition, possible protein‑energy malnutrition (PEM) | Negative energy balance, loss of lean body mass. |
| Muscle wasting (temporal, clavicular, quadriceps) | Protein deficiency, chronic catabolism | Reduced synthesis of muscle proteins, increased proteolysis. |
| Skin changes – dry, thin, hyperpigmented, “flaky paint” dermatitis | Vitamin A, C, B2, niacin deficiency | Impaired epithelial maintenance, antioxidant deficiency. |
| Hair changes – thinning, loss, “flag sign” (coarse, pigmented) | Protein, zinc, biotin deficiency | Keratin synthesis requires adequate protein and trace elements. |
| Glossitis, angular cheilitis | B‑complex (B2, B3, B6, B12, folate) deficiency | Rapidly dividing mucosal cells need folate/B‑vitamins. |
| Peripheral neuropathy – stocking‑glove loss of sensation, diminished reflexes | B1, B6, B12 deficiency | Vitamins required for neuronal metabolism and myelin formation. |
| Bleeding gums, petechiae, easy bruising | Vitamin C deficiency | Impaired collagen synthesis → fragile capillaries. |
| Scleral icterus, jaundice | Fat‑soluble vitamin malabsorption (A, D, E, K) secondary to cholestasis | Bile needed for absorption of these vitamins. |
| Bone tenderness, deformities, muscle pain | Vitamin D deficiency, calcium deficiency | Impaired mineralisation of bone matrix. |
| Cardiovascular signs – tachycardia, hypotension, peripheral edema | Severe protein deficiency (hypoalbuminemia) | Reduced oncotic pressure → third‑spacing. |
| Neurological signs – confusion, ataxia, seizures | Thiamine (B1) deficiency (Wernicke’s) or severe B12 deficiency | Energy failure in CNS neurons. |
| Palmar erythema, spider angiomas | Chronic liver disease with fat‑soluble vitamin loss | Impaired synthesis and storage of vitamins. |
Differential diagnosis
| Condition | Points toward it | How it separates from nutritional deficiency |
|---|---|---|
| Protein‑energy malnutrition (PEM) | Low BMI, muscle wasting, edema, history of food insecurity | Improves with caloric repletion; labs show low albumin, pre‑albumin without specific vitamin abnormalities. |
| Iron‑deficiency anemia | Fatigue, pallor, pica, microcytic anemia | Iron studies (low ferritin, low serum iron) differentiate; not associated with classic vitamin‑specific signs. |
| Sickle‑cell disease crisis | Known sickle‑cell, vaso‑occlusive pain, hemolysis | Hemoglobin electrophoresis positive; crises episodic, not chronic malabsorption. |
| Chronic kidney disease | Edema, hypertension, reduced GFR, uremic symptoms | Labs show elevated creatinine, altered electrolytes; vitamin D deficiency secondary to renal conversion loss. |
| HIV‑associated wasting | HIV positive, opportunistic infections, ART side‑effects | CD4 count low, viral load high; wasting may be multifactorial but ART‑related B6 depletion is a clue. |
| Tuberculosis (active) | Chronic cough, night sweats, weight loss, positive sputum | Radiographic infiltrates, positive GeneXpert; TB can cause B6 loss but also systemic catabolism. |
| Malabsorption syndromes (celiac, tropical sprue, chronic pancreatitis) | Steatorrhea, abdominal pain, weight loss, specific nutrient deficiencies | Stool fat excess, duodenal biopsy (celiac) or response to antibiotics (tropical sprue). |
| Chronic liver disease (cirrhosis) | Jaundice, ascites, spider angiomas, alcohol use | Coagulopathy, elevated transaminases; fat‑soluble vitamin loss secondary to cholestasis. |
Investigations
| Test | What it answers | Interpretation |
|---|---|---|
| BMI, MUAC | Nutritional status | BMI <18.5 or MUAC <23 cm = undernutrition |
| Serum albumin / pre‑albumin | Protein reserves | Low values suggest protein deficiency, but also inflammation |
| Complete blood count | Anemia type, infection | Microcytic → iron; macrocytic → B12/folate; leukocytosis → infection |
| Serum electrolytes, renal function | Catabolic state, organ involvement | Hyponatremia, elevated creatinine may accompany severe malnutrition |
| Serum vitamin levels (A, D, B12, folate, thiamine, pyridoxine, C) | Specific micronutrient status | Deficient if below reference range; note acute phase may lower levels |
| Urine organic acids | Thiamine, riboflavin deficiency | Elevated lactate, α‑ketoglutarate suggest B1 loss |
| Stool analysis (fat, parasites) | Malabsorption, tropical infections | Fat >7 g/24 h = steatorrhoea; ova/cysts indicate parasitic disease |
| Chest X‑ray / sputum GeneXpert | Active TB | Cavitary lesions or positive MTB PCR confirm TB |
| HIV test (4th generation) | HIV status | Positive → higher risk of wasting and specific deficiencies |
| Liver function tests | Fat‑soluble vitamin absorption | Low albumin, raised ALP, bilirubin indicate cholestasis |
| Bone mineral density (if available) | Chronic vitamin D/calcium deficiency | T‑score ≤‑2.5 = osteopenia/osteoporosis |
Diagnosis and severity
| Category | Criteria | Severity grading |
|---|---|---|
| Protein‑energy malnutrition | BMI <18.5 kg/m² or MUAC <23 cm plus at least two clinical signs (muscle wasting, edema, low albumin) | Mild: BMI 16‑18.5, no edema; Moderate: BMI 14‑16, mild edema; Severe: BMI <14 or presence of marked edema/ascites |
| Micronutrient deficiency | Specific serum level below laboratory reference and compatible clinical signs | Mild: level 0.8‑1.0 × lower limit, isolated symptom; Moderate: 0.5‑0.8 × lower limit, multiple symptoms; Severe: <0.5 × lower limit, life‑threatening manifestations (e.g., Wernicke’s, severe anemia) |
| Combined deficiency | Two or more micronutrient levels deficient or protein‑energy malnutrition plus micronutrient loss | Graded by the most severe component; management addresses both. |
Clinical decision:
- Confirm the primary driver (energy deficit vs. specific vitamin loss).
- Stage severity to guide urgency of re‑feeding, need for inpatient monitoring (electrolyte shifts, re‑feeding syndrome), and whether parenteral supplementation is required.
Key safety points:
- In severe PEM, start with low‑calorie feeds and monitor electrolytes (especially phosphate, potassium, magnesium).
- For thiamine deficiency, give parenteral thiamine before glucose infusion to avoid precipitating Wernicke’s.
- Vitamin D repletion in renal disease should be with active analogues; monitor calcium and phosphate.
This framework equips the junior doctor to recognise, differentiate, and stage nutrition‑related presentations common in Kenyan clinical rotations, and to initiate safe, evidence‑based management.
Management
| Step | What to do | Rationale / safety notes |
|---|---|---|
| Immediate stabilisation | • Assess airway, breathing, circulation; give O₂ if hypoxic. <br>• Correct severe electrolyte or fluid loss with isotonic IV fluids. <br>• Treat hypoglycaemia with dextrose bolus (if unconscious). | Prevents life‑threatening shock, cerebral oedema and cardiac arrhythmia. |
| Re‑feeding | • Start low‑calorie enteral feeding (≈10 kcal/kg/day) and increase by 10–20 % daily. <br>• Monitor for re‑feeding syndrome (phosphate, magnesium, potassium). | Gradual increase avoids sudden insulin surge and electrolyte shifts. |
| Micronutrient replacement | • Give oral/IV multivitamin‑mineral complexes (B‑complex, vitamin C, vitamin D, zinc, selenium). <br>• Specific therapy: <br> – Vitamin A (for xerophthalmia, measles‑related deficiency) – give as oral/IM retinol ester. <br> – Vitamin B1 (thiamine) – give before glucose infusion to prevent Wernicke’s. <br> – Vitamin B12 (cobalamin) – give intramuscular cyanocobalamin in pernicious anaemia or malabsorption. <br> – Folate – give oral folic acid in macrocytic anaemia or pregnancy. | Replace the deficient vitamin before giving carbohydrate loads; avoid precipitating neurologic injury. |
| Treat underlying disease | • Antiretroviral therapy for HIV, anti‑TB drugs, antimalarials, disease‑modifying agents for rheumatic disease, hydroxyurea for sickle cell. | Improves appetite, absorption and reduces catabolic drive. |
| Nutritional counselling | • Energy‑dense, locally available foods (maize, beans, groundnuts, leafy greens). <br>• Small frequent meals, fortified porridges, use of oil or butter for added calories. | Sustainable long‑term correction; respects cultural diet. |
| Monitoring | • Daily weight, fluid balance, vitals. <br>• Electrolytes (phosphate, potassium, magnesium) every 24 h for first 5 days. <br>• Haematology (Hb, MCV) weekly; serum vitamin levels where available. | Detects re‑feeding syndrome, treatment response, and need for dose adjustment. |
| Follow‑up | • Outpatient review at 2 weeks, then monthly until nutritional targets met. <br>• Repeat full blood count and relevant vitamin assays at 3 months. | Ensures complete recovery and identifies late complications. |
| Contra‑indications / safety | • High‑dose vitamin A in pregnancy (teratogenic). <br>• Thiamine in alcoholic patients – give before glucose. <br>• Intravenous iron in active infection without antibiotics. | Avoid iatrogenic harm; respect drug‑disease interactions. |
Complications and prognosis
- Re‑feeding syndrome – hypophosphataemia, arrhythmias, respiratory failure; prevent with slow caloric increase and electrolyte monitoring.
- Neurologic sequelae – irreversible Wernicke’s encephalopathy if thiamine omitted; peripheral neuropathy from B12 deficiency may persist.
- Ophthalmic damage – xerophthalmia and corneal ulceration if vitamin A not promptly replaced.
- Hematologic effects – persistent macrocytic anaemia, pancytopenia if folate/B12 deficiency untreated.
- Growth retardation in children; impaired wound healing and immune function in adults.
- Prognosis – excellent when deficiency identified early and treated appropriately; delayed treatment leads to higher morbidity and mortality, especially in HIV/TB co‑infection.
High‑yield exam points
- Look‑alike conditions: Kwashiorkor vs. marasmus (edema vs. severe wasting); pellagra vs. photosensitive drug reaction (dermatitis, diarrhea, dementia).
- Common wrong first step: Giving glucose bolus before thiamine in an alcoholic or malnourished patient – precipitates Wernicke’s.
- Examiner bedside questions:
- “What vitamin deficiency explains the patient’s peripheral neuropathy and macrocytosis?”
- “Why do you start feeding at 10 kcal/kg rather than full requirement?”
- “Which electrolyte do you monitor most closely in the first 72 h of re‑feeding?”
- “How would you differentiate vitamin A deficiency from measles‑related conjunctivitis?”
Clinical case
Case: A 34‑year‑old man with newly diagnosed HIV (CD4 150 cells/µL) presents with 3 weeks of progressive weakness, confusion, and a “stiff‑leg” gait. He has a thin habitus, dry scaly rash on the hands, and a blood pressure of 100/60 mmHg. Labs show Hb 9 g/dL, MCV 112 fL, serum phosphate 0.6 mmol/L (low), and normal glucose.
Questions
- What is the most likely vitamin deficiency?
Answer: Thiamine (vitamin B1) deficiency – classic triad of confusion, ataxia, and cardiac dysfunction (wet beriberi) in a malnourished HIV patient.
- What immediate treatment should be given before any glucose?
Answer: Intravenous thiamine (B1) – prevents precipitating Wernicke’s encephalopathy when glucose is later administered.
- Which long‑term nutritional strategy will best prevent recurrence?
Answer: Structured, energy‑dense diet with regular multivitamin‑mineral supplementation and ART to improve immune status and appetite.
Practice questions
Question 1
A 6‑month‑old infant from a rural Kenyan village is brought with irritability, vomiting, and a swollen, “floppy” abdomen. The child is lethargic, has a protuberant belly, and the skin shows “cracked” patches on the elbows. What is the next best step?
A. Start high‑dose vitamin A oral therapy
B. Give oral rehydration solution only
C. Begin low‑calorie enteral feeding with thiamine supplementation
D. Administer intravenous antibiotics
Answer: C. Begin low‑calorie enteral feeding with thiamine supplementation
Explanation: The picture is classic for kwashiorkor; thiamine must be given before carbohydrate loads to avoid Wernicke’s, and feeding should start slowly to prevent re‑feeding syndrome.
Question 2
A 45‑year‑old woman with sickle cell disease presents with painful leg ulcers, night blindness, and dry, scaly skin. Which deficiency explains all three findings?
A. Vitamin D
B. Vitamin A
C. Vitamin C
D. Zinc
Answer: B. Vitamin A
Explanation: Vitamin A deficiency causes night blindness, xerosis cutis, and impairs epithelial repair leading to ulceration.
Question 3
A patient on long‑term isoniazid therapy for TB develops peripheral neuropathy. Which supplement should be added to prevent worsening?
A. Vitamin B12
B. Vitamin B6 (pyridoxine)
C. Folic acid
D. Vitamin C
Answer: B. Vitamin B6 (pyridoxine)
Explanation: Isoniazid interferes with pyridoxine metabolism; supplementation prevents neuropathy.
Question 4
A 28‑year‑old man with malaria is found to have haemolytic anaemia, jaundice, and low serum folate. Which of the following is the most appropriate micronutrient intervention?
A. Oral folic acid daily
B. Intravenous vitamin B12 weekly
C. High‑dose vitamin C infusion
D. No supplementation needed
Answer: A. Oral folic acid daily
Explanation: Folate is depleted in malaria‑related haemolysis; replacement aids erythropoiesis.
Question 5
During re‑feeding of a severely malnourished patient, serum phosphate falls dramatically. Which action is correct?
A. Stop feeding completely for 48 h
B. Increase carbohydrate load to raise insulin
C. Give intravenous phosphate while continuing gradual feeding
D. Switch to a high‑fat, low‑carbohydrate diet only
Answer: C. Give intravenous phosphate while continuing gradual feeding
Explanation: Re‑feeding syndrome is managed by correcting phosphate deficits while maintaining the feeding plan; stopping feeding worsens catabolism.
Drafted with AI assistance from standard references and reviewed for structure. Check details against your lecture notes and the Kenya MoH guideline.