Vitamin D

Body function

Calcium absorption; immune modulation; mood regulation; musculoskeletal health

Daily requirement

600–800 IU/day; many experts recommend 1000–2000 IU especially in low-sun climates

Deficiency signs

Fatigue, low mood, bone pain, frequent infections, muscle weakness

Excess risks

Hypercalcaemia at very high supplemental doses (>4000 IU/day long-term without testing)

At-risk groups

People with limited sun exposure, darker skin tones, older adults, office workers

Supplement forms

D3 (cholecalciferol) preferred over D2; softgels, drops, tablets

Food sources

Salmon (grilled) — ~570 IU (14 mcg) vitamin D per 100g grilled fillet
Eggs (whole, boiled) — ~41 IU (1 mcg) vitamin D per egg, mostly in the yolk
Fortified oat milk — ~100 IU (2.5 mcg) vitamin D per cup, fortified

Related symptoms

Educational information only — not medical advice. This content does not diagnose, treat, or replace consultation with a qualified healthcare professional. Always seek professional medical advice for symptoms, supplement use, or health concerns.