Vitamin B Complex: Deficiencies, RDA, and Sources

• Vitamin B complex deficiency can cause multiple manifestations.

Vitamin B Complex: RDA and Dietary Sources

• Thiamine (B1): RDA - 0.4 mg/1000 kcal; Dietary sources - Unpolished rice, oats, legumes, wheat, meat.
• Riboflavin (B2): RDA - 0.4-1.2mg/1000 kcal; Dietary sources - Milk, green leafy vegetables, sprouts, legumes, meat.
• Niacin (B3): RDA - 6-8 mg/1000 kcal; Dietary sources - Milk, green leafy vegetables, sprouts, legumes, meat.
• Pyridoxine (B6): RDA - 0.3-1 mg/day; Dietary sources - Banana, wheat germ, rice, sunflower seeds.
• Cobalamin (B12): RDA - 0.3-0.5 mg; Dietary sources - Milk, meat, eggs (not found in plant sources).
• Folate: RDA - 0.5-1 mg; Dietary sources - Green leafy vegetables, citrus fruits, papaya.
• Biotin: RDA - 1-10 mg; Dietary sources - Fruits, organ meats.

Clinical Features of Vitamin B Deficiency

Thiamine Deficiency

• It is predominantly due to the intake of polished rice, GI (gastrointestinal), or liver disease.
• Beri-Beri can occur with thiamine deficiency.
• Wet Beri-Beri can include features of congestive cardiac failure like edema and respiratory distress.
• Dry Beri-Beri involves neurological features such as irritability, weakness of lower limbs, and diminished DTRs (Deep tendon reflexes).

Niacin Deficiency

• Niacin deficiency gives rise to Pellagra, a disease of the 4 D's.
• The 4 D's of pellagra are Diarrhoea, Dermatitis, Dementia (early onset), and Death.
• Pellagra-like rashes can be seen in metabolic disorders like Hartnup disease (impaired transport of neutral amino acid).

Pyridoxine Deficiency

• Pyridoxine deficiency in the neonatal or infantile period can lead to refractory seizures.
• If a child has refractory seizures not controlled by antiepileptics, consider pyridoxine deficiency and try a 100 mg dose of pyridoxine.
• Older children can have peripheral neuropathy, anemia, or dermatitis due to pyridoxine deficiency.
• Drugs like Isoniazid can predispose individuals to pyridoxine deficiency.

Riboflavin (Vit B2) Deficiency

• Riboflavin deficiency can cause glossitis, cheilosis (inflammation of lips), angular stomatitis (painful lesions near the angle of the mouth), seborrheic dermatitis along the nasolabial folds, and photophobia.

Cobalamin Deficiency

• Hematological manifestation is megaloblastic anemia.
• Neurological manifestation is subacute combined degeneration of spinal cord.

Folate Deficiency

• It can give rise to megaloblastic anemia, growth restriction, and glossitis.
• Folate deficiency during pregnancy can increase the risk of neural tube defects in the baby such as myelocele and meningomyelocele.

Biotin Deficiency

• Biotin deficiency can cause alopecia, skin rashes like periorificial scaly dermatitis, conjunctivitis, glossitis, anorexia, vomiting, and neurological manifestations like developmental delay or seizures.

Vitamin C (Ascorbic Acid)

Normal Function

• It helps in the formation of collagen.
• It is required for the maintenance of normal connective tissue & wound healing and bone formation or osteoid formation.
• It helps in iron absorption from the gut by reducing ferrous to ferric state.

RDA of Vitamin C

• Infants: 30-40 mg/day
• Children: 40-70 mg/day

Dietary Sources of Vitamin C

• Dietary sources include citrus fruits like orange and lime.
• Also found in vegetables like cauliflower, cabbage, cucumber, and spinach.