Vitamin B deficiencies refer to a group of disorders resulting from inadequate levels of one or more water-soluble B-complex vitamins, which function primarily as metabolic co-enzymes in cellular energy production, neurological function, hematopoiesis, and DNA synthesis.

The B-complex vitamins include:

Deficiency often occurs as multiple vitamin deficiency rather than isolated deficiency, especially in:

• Malnutrition

• Chronic alcoholism

• Chronic illness

• Malabsorption

Because B vitamins are not stored extensively (except B12), deficiency may develop within weeks to months.

2. Pathophysiology

B-complex vitamins act as coenzymes in metabolic pathways.

Deficiency leads to failure of high-energy and rapidly dividing tissues:

3. Risk Factors

Nutritional

• Starvation

• Protein-energy malnutrition

• Elderly with poor intake

• Food insecurity

Medical Conditions

• Chronic diarrhoea

• Malabsorption syndromes

• Chronic liver disease

• Chronic kidney disease

• HIV/AIDS

• Cancer

• Hyperthyroidism

Lifestyle

• Chronic alcoholism (most common cause)

• Eating disorders

Drug-Induced

4. Clinical Features

Symptoms often overlap due to multiple deficiencies.

General Symptoms

• Fatigue

• Weakness

• Weight loss

• Irritability

• Poor appetite

Neurological

• Peripheral neuropathy

• Paresthesia

• Burning feet

• Ataxia

• Memory impairment

• Confusion

• Depression

• Wernicke encephalopathy

Hematological

• Megaloblastic anaemia

• Microcytic anaemia

• Pancytopenia

Gastrointestinal

• Glossitis (beefy tongue)

• Angular stomatitis

• Diarrhoea

• Malabsorption

Dermatological

• Seborrheic dermatitis

• Hyperpigmentation

• Photosensitive rash

• Cracked lips

Cardiovascular

• Tachycardia

• Heart failure (thiamine deficiency)

5. Diagnostic Criteria

Diagnosis is based on:

1. Compatible clinical features

2. Presence of risk factors

3. Response to vitamin replacement therapy

In resource-limited settings, treatment is often initiated empirically.

6. Investigations

Basic Tests

Specific Vitamin Levels (if available)

Additional Tests

• Liver function tests

• Renal profile

• HIV testing (if indicated)

7. Management

Treatment should begin immediately once suspected to prevent permanent neurological damage.

A. Non-Pharmacological

Lifestyle

• Balanced diet restoration

• Discourage alcohol abuse

• Treat underlying disease

Nutritional Rehabilitation

• High-protein diet

• Fresh fruits and vegetables

• Fortified cereals

• Animal protein sources

B. Pharmacological

For all forms of vitamin B deficiencies

• Vitamin B complex, oral2 tablets three times daily for 1 weekthen1 tablet daily for 3 months

When Severe Neurological Symptoms Present

Give parenteral therapy first before oral therapy (especially suspected B1 deficiency) to prevent irreversible brain injury.

8. Monitoring

9. Complications if Untreated

• Permanent neuropathy

• Dementia

• Cardiomyopathy

• Severe anaemia

• Death (Wernicke encephalopathy)

10. Prevention

Individual Prevention

• Balanced diet

• Limit alcohol intake

• Supplementation in high-risk patients

High-Risk Groups Requiring Routine Supplementation

• Alcohol dependence

• HIV infection

• TB treatment patients

• Elderly

• Post-surgery patients

Recommended Preventive Strategy

• Multivitamin supplementation

• Food fortification programs

• Nutrition education

11. Prognosis

• Excellent with early treatment

• Neurological damage may become permanent if treatment delayed

• Alcohol-related deficiency has higher relapse risk