Sources, Functions, and Deficiency Symptoms of Vitamin B Complex

Vitamin B: Sources, Functions, and Deficiency

Vitamin B is a group of water-soluble vitamins that play a critical role in cell metabolism. Since they are water-soluble, they are not stored in large amounts in the body (except B12) and must be regularly supplied through the diet.

1. Vitamin B1 (Thiamine)

Sources: Whole grains, yeast, pulses, nuts, and pork.

Functions: Acts as a coenzyme (TPP) in carbohydrate metabolism and is essential for nerve and muscle function.

Deficiency Symptoms:

• Beri-beri: Characterized by muscle wasting (Dry Beri-beri) or edema and heart failure (Wet Beri-beri).
• Wernicke-Korsakoff syndrome (common in chronic alcoholism).

2. Vitamin B2 (Riboflavin)

Sources: Milk, eggs, leafy vegetables, and liver.

Functions: Component of FAD and FMN; vital for energy production and maintaining healthy skin and vision.

Deficiency Symptoms:

• Cheilosis: Cracking at the corners of the mouth.
• Glossitis (magenta-colored tongue) and photophobia.

3. Vitamin B3 (Niacin)

Sources: Meat, fish, poultry, whole grains, and legumes.

Functions: Precursor to NAD and NADP; essential for DNA repair and steroid hormone production.

Deficiency Symptoms:

• Pellagra: Characterized by the "4 Ds" — Dermatitis, Diarrhea, Dementia, and eventually Death.

4. Vitamin B9 (Folic Acid)

Sources: Green leafy vegetables (foliage), citrus fruits, and fortified cereals.

Functions: Required for DNA synthesis and red blood cell formation. Crucial during pregnancy for fetal brain development.

Deficiency Symptoms:

• Megaloblastic Anemia: Large, immature red blood cells.
• Neural Tube Defects (NTDs) in newborns if deficient during pregnancy.

5. Vitamin B12 (Cobalamin)

Sources: Exclusively found in animal products (meat, milk, eggs). Vegans often require supplements.

Functions: Maintenance of the myelin sheath (nervous system) and maturation of RBCs.

Deficiency Symptoms:

• Pernicious Anemia: Due to lack of 'Intrinsic Factor' for absorption.
• Irreversible neurological damage and tingling in hands and feet.

Summary Table

Vitamin	Chemical Name	Major Function	Key Deficiency Disease
B1	Thiamine	Carbohydrate metabolism	Beri-beri
B2	Riboflavin	Redox reactions	Ariboflavinosis
B3	Niacin	Energy transfer	Pellagra
B9	Folic Acid	DNA Synthesis	Megaloblastic Anemia
B12	Cobalamin	Nerve health / RBCs	Pernicious Anemia

Conclusion

Vitamin B complex components often work synergistically. A balanced diet rich in whole foods is typically sufficient to prevent deficiencies, which can otherwise lead to severe neurological and hematological disorders.

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VIMALA COLLEGE (AUTONOMOUS), THRISSUR
SECOND SEMESTER UG DEGREE EXAMINATION, APRIL 2025
VMFYUGP : MDC - Chemistry
CHE2FM106 : CHEMISTRY IN DAILY LIFE