Low-Dose Vitamin D3 (Cholecalciferol)
Mechanism of Action
Converted to active form 1,25-dihydroxyvitamin D (calcitriol), which regulates calcium absorption, bone metabolism, immune function, and has pleiotropic effects on many tissues.
Indications
Low-Dose formulation. Deficiency prevention and treatment (universal in lunar residents without supplementation), osteoporosis prevention, immune support, mood support.
Dosing
Standard (Earth)
See Low-Dose prescribing information. Maintenance: 1000-4000 IU daily. Deficiency treatment: 50,000 IU weekly for 8 weeks.
Lunar Protocol
Universal supplementation for all lunar residents: minimum 2000 IU daily. First 3 months of residence: 4000 IU daily (loading). Quarterly monitoring of 25-OH vitamin D levels — target 75-125 nmol/L. In residents with concurrent bone loss: up to 6000 IU daily (combined with calcium). Magnesium supplementation required for optimal vitamin D activation.
Storage
Standard
Room temperature, protect from light.
Lunar (Radiation + Temperature)
Very stable at room temperature. Protect from light and temperature extremes. 2-year expiry for soft gel capsules. Tablet form slightly more stable. Radiation shielded. Maintain 24-month supply for entire habitat population — this is prophylactic medication for every resident.
Supply Chain & Lunar Pharmacy Notes
Must be stocked for EVERY resident. Universal supplementation is mandatory policy. Bulk procurement for colony-wide distribution. Cost-effective — one of the most important disease prevention medications in lunar formulary.
Drug Interactions
Thiazide diuretics (hypercalcemia risk). Digoxin (toxicity with hypercalcemia). Certain anticonvulsants reduce efficacy.
Contraindications
Hypercalcemia, hypervitaminosis D. Monitor calcium levels with high-dose therapy.
Side Effects
Toxicity with excessive doses: hypercalcemia, hypercalciuria, renal stones. Rare at recommended doses.
Lunar Alternatives
Ergocalciferol (D2) — less potent, less preferred. UV light therapy lamps (adjunct, not replacement).