Vitamins and supplements

Vitamins and supplements

Drug monograph · NCLEX study reference
Trade names	B1, B12, B6, B3
Therapeutic class	Vitamin and supplement
Pharmacologic class	Fat-soluble and water-soluble vitamins
Onset / peak / duration	Correction over days to weeks.
Half-life / level	Variable; monitor target labs (such as vitamin D level, B12, folate).
Routes	PO (oral), IV, IM, SubQ
High-alert (ISMP)	No
Black box warning	None
Antidote / reversal	Not generally applicable.
Pregnancy / lactation	Folic acid recommended in pregnancy; others as needed.

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Vitamins and supplements (brand names B1, B12, B6, B3) — Vitamin and supplement; Fat-soluble and water-soluble vitamins.

Identification

• Therapeutic class: Vitamin and supplement.
• Pharmacologic class: Fat-soluble and water-soluble vitamins.

Pharmacology

• Mechanism of action: Replace deficient vitamins essential to metabolism, bone, blood, and nerve function.
• Onset / peak / duration: Correction over days to weeks.
• Half-life / therapeutic level: Variable; monitor target labs (such as vitamin D level, B12, folate).

Clinical use

• Indications: Vitamin D deficiency and bone health, vitamin K for clotting and warfarin reversal, thiamine for deficiency and Wernicke encephalopathy and alcohol use, folic acid for deficiency and pregnancy and methotrexate adjunct, B12 for pernicious anemia, pyridoxine to prevent isoniazid neuropathy, vitamin C and niacin as indicated.
• Usual dose, route, frequency: Mostly PO; B12 IM for pernicious anemia; thiamine IV or IM in deficiency; phytonadione PO, SubQ, or slow IV.
• Maximum dose / adjustments: Fat-soluble vitamins (A, D, E, K) can accumulate and cause toxicity; avoid excess.

Safety

• Contraindications: Hypersensitivity.
• Black box warning: None.
• Interactions: Vitamin K opposes warfarin (keep intake consistent), folic acid can mask B12 deficiency, niacin with statins (myopathy), pyridoxine reduces levodopa effect.
• Pregnancy / lactation: Folic acid recommended in pregnancy; others as needed.
• High-alert: No.

Adverse effects

• Common side effects: Usually minimal; niacin causes flushing; oral iron-like GI upset with some.
• Serious effects to report: Fat-soluble vitamin toxicity, anaphylaxis with IV phytonadione (give slowly), severe niacin flushing.
• Antidote / reversal: Not generally applicable.

Nursing process

• Assessment before administration: Relevant levels, deficiency cause, diet, medication interactions.
• Interventions during therapy: Give thiamine before or with glucose in suspected deficiency (prevents Wernicke); give IV phytonadione slowly; pair pyridoxine with isoniazid.
• Monitor: Target vitamin levels and related labs, symptom resolution.
• Evaluation / expected outcome: Corrected deficiency.

Patient teaching

• Patient teaching: Take as directed; do not megadose fat-soluble vitamins; keep vitamin K intake steady if on warfarin; take niacin with food and expect flushing (aspirin pretreatment may help).
• Notify provider if: Signs of toxicity, severe flushing, no improvement.
• Administration tips: Thiamine before glucose in deficiency; IV phytonadione slow; consistent vitamin K with warfarin.