Multivitamin [Adult preparation]

Approved Indications:

• Prevention of Micronutrient Deficiencies in adults with:
• Poor dietary intake (e.g., low-calorie diets, elderly individuals, anorexia)
• Chronic diseases (e.g., diabetes, cancer, GI disorders)
• Recovery from surgery, trauma, or prolonged illness
• Supplementation During Increased Nutritional Demand, such as:
• Pregnancy and lactation (when using specific prenatal formulations)
• Physical or mental stress
• Post-bariatric surgery
• Supportive Care in Alcohol Use Disorder (especially thiamine, folate, B12)

Clinically Accepted Off-label Uses:

• Adjunctive therapy in malabsorption syndromes, such as celiac disease, Crohn’s disease, or chronic pancreatitis
• Cognitive support in elderly individuals at risk of B-vitamin deficiencies
• Prevention of complications during long-term use of certain medications, e.g., methotrexate (folic acid), isoniazid (B6)

Adults (≥18 years):

• Standard Dose: 1 tablet or capsule orally once daily with food.
• Formulation: Typically contains essential vitamins (A, D, E, C, B1, B2, B3, B5, B6, B7, B9, B12) and minerals (iron, calcium, magnesium, zinc, selenium, iodine, copper, manganese, chromium, molybdenum).

Elderly:

• Same as standard adult dose. Prefer preparations with increased vitamin D, B12, and calcium.

Pregnant/Lactating Women:

• Use specific prenatal multivitamins, typically with:
• Folic acid 400–800 mcg
• Iron 27–30 mg
• Iodine 150 mcg
• Vitamin D 600–1000 IU
• One tablet daily with food

Renal Impairment:

• Avoid high-dose potassium, magnesium, and vitamin A.
• Select renal-safe multivitamin formulations.

Hepatic Impairment:

• Avoid excess vitamin A and iron.
• Use with caution and under medical supervision.

Administration Notes:

• Oral route only.
• Take with meals to improve absorption and reduce GI discomfort.

Multivitamin supplements replenish essential nutrients that serve as cofactors or substrates in a wide range of metabolic processes. B-complex vitamins (B1, B2, B3, B6, B12, folate) support energy production, DNA synthesis, and nervous system function. Vitamin C acts as an antioxidant and aids in collagen formation. Fat-soluble vitamins (A, D, E, K) are critical for immune function, bone metabolism, vision, and coagulation. Minerals like zinc, selenium, and copper regulate enzymatic activity, antioxidant defense, and cellular repair. Regular supplementation corrects or prevents subclinical deficiencies that may impair systemic health.

Absorption:

• Water-soluble vitamins (B-complex, C): Absorbed in the small intestine; excess excreted in urine.
• Fat-soluble vitamins (A, D, E, K): Absorbed with dietary fat via lymphatic system; stored in adipose tissue and liver.

Distribution:

• Varies by vitamin: water-soluble circulate freely in plasma; fat-soluble are protein-bound and stored.

Metabolism:

• B-vitamins and others are metabolized hepatically into active coenzyme forms.
• Vitamin D is hydroxylated in the liver and kidney to its active form (calcitriol).

Excretion:

• Water-soluble: primarily renal.
• Fat-soluble: mainly via feces (biliary elimination).

Onset of Effect:

• Effects vary: hematologic improvements (e.g., with folate, B12) typically within 2–4 weeks.

Pregnancy:

• Generally safe when taken as prenatal preparations within recommended daily allowances.
• Excess vitamin A (retinol >10,000 IU/day) may be teratogenic—avoid high doses.

Lactation:

• Safe and beneficial. Supports maternal nutrient stores and breastmilk composition.
• Choose products labeled safe for nursing mothers.

Caution:

• Avoid self-medicating with multiple vitamin sources to prevent overdose.

• Primary Class: Nutritional Supplement
• Subclass: Oral Multivitamin–Mineral Combination (Adult Formulation)

• Known hypersensitivity to any component.
• Iron overload conditions (e.g., hemochromatosis) — if iron-containing.
• Hypervitaminosis A or D.
• Severe renal impairment — avoid potassium-, magnesium-, or phosphate-containing formulations.
• Concurrent use of vitamin K in patients on warfarin without monitoring.

• Do not exceed daily upper limits for fat-soluble vitamins (A, D, E, K) to avoid toxicity.
• Iron-containing multivitamins may cause constipation or GI upset.
• Vitamin K may interfere with anticoagulant therapy (e.g., warfarin).
• Excess vitamin B6 (>100 mg/day) may cause peripheral neuropathy.
• Vitamin C in high doses (>2 g/day) may cause kidney stones or GI discomfort.

Common:

• GI symptoms: nausea, constipation, bloating, abdominal discomfort
• Discolored urine (bright yellow from riboflavin)

Less Common:

• Headache, dizziness, metallic taste

Rare but Serious:

• Allergic reactions: rash, urticaria, angioedema
• Hypervitaminosis (especially A, D, iron): fatigue, irritability, liver toxicity

Timing:
Generally mild, dose-dependent, and transient. GI effects are often reduced when taken with food.

• Tetracyclines, fluoroquinolones: Chelation with iron/calcium reduces antibiotic absorption; separate by 2–4 hours.
• Levothyroxine: Iron/calcium impair absorption; separate by 4 hours.
• Warfarin: Vitamin K can reduce anticoagulant effect.
• Phenytoin, carbamazepine: May decrease vitamin D and folate levels.
• Alcohol and chronic illness: Increase risk of B-vitamin depletion.

No major CYP450-mediated interactions expected.

• WHO (2022–2023): Reiterated the importance of tailored multivitamin use, particularly for pregnant women in low- and middle-income countries.
• USPSTF (2022): Found insufficient evidence to support routine use in healthy adults for chronic disease prevention, but recognized benefit in populations at risk for deficiency.
• FDA Reminder (2021): Advised caution with high-dose biotin due to interference with lab tests.

• Temperature: Store at 15°C to 30°C (59°F to 86°F)
• Humidity/Light: Protect from excessive moisture and direct sunlight.
• Handling: Keep out of reach of children. Do not crush extended-release forms.
• Refrigeration: Not required. Avoid freezing.
• Shelf Life: Follow expiration date on package; discard if color/odor changes.