Vitamin D3: Benefits, Dosage & Research
A secosteroid hormone synthesized in the skin upon UVB exposure. Critical for immune function, bone health, mood regulation, and cognitive performance. An estimated 42% of American adults are deficient.
Source
Sunlight (UVB on bare skin), fatty fish, egg yolks, fortified foods. Supplemental D3 (cholecalciferol) from lanolin or lichen (vegan). Always pair with K2 for proper calcium metabolism.
Researched Benefits
- Supports immune system function and resilience
- Critical for calcium absorption and bone health
- Supports mood regulation and reduces seasonal affective symptoms
- Associated with improved cognitive function and reduced dementia risk
Dosage & Protocol
2,000-5,000 IU daily for maintenance. Higher doses may be needed to correct deficiency (test first). Take with a meal containing fat. Pair with K2 (100-200mcg MK-7).
Safety & Interactions
Fat-soluble -- can accumulate to toxic levels with chronic overdosing (above 10,000 IU/day long-term). Get blood levels tested (target 40-60 ng/mL). May interact with certain medications (steroids, statins, thiazide diuretics).
