Vitaminrepletion

Vitamin repletion is the clinical process of restoring normal vitamin status after deficiency or suboptimal intake. It involves identifying the deficient nutrient, assessing the severity, and choosing an appropriate route and dose of replenishment to restore tissue stores and functional health.

Assessment typically combines dietary history, symptom review, and laboratory measurements. Serum levels are common, but some vitamins require functional or surrogate tests (for example, methylmalonic acid for B12 status, red cell folate, or 25-hydroxyvitamin D for vitamin D). Clinical signs and risk factors such as pregnancy, older age, malabsorption, or chronic illness inform the evaluation.

Approaches to repletion vary by vitamin and context. Mild deficiencies may improve with diet alone, while moderate to severe deficits or malabsorption often require supplements. Fat-soluble vitamins (A, D, E, K) carry a greater risk of accumulation and toxicity with excessive intake, especially in liver or kidney disease, whereas water-soluble vitamins are generally less prone to toxicity but can still cause adverse effects at very high doses. Treatment plans consider ongoing needs, maintenance dosing, and potential interactions with medications.

Examples include vitamin D repletion with cholecalciferol or ergocalciferol in loading and maintenance phases; vitamin B12 deficiency, particularly pernicious anemia, often requiring intramuscular or high-dose oral cyanocobalamin or hydroxocobalamin, followed by maintenance therapy; and folate supplementation in cases of deficiency after ruling out concurrent B12 deficiency.

Monitoring during repletion tracks symptom improvement and laboratory values over weeks to months, guiding dose adjustments and duration. Special populations, such as pregnant individuals, the elderly, those with malabsorption, or post-bariatric surgery, may require tailored regimens and closer follow-up.