Vitamin D
Vitamin D is involved in bone health and calcium use. Considered by people with limited sun exposure.
What it is
A fat-soluble vitamin also made in skin with sun exposure.
Role in the body
Supports calcium absorption and bone maintenance.
Why people consider it
Considered by people who spend a lot of time indoors or in low-sun seasons.
Food sources
- Salmon
- Mushrooms
- Egg yolk
- Fortified foods
Typical labeled usage
Follow the labeled serving.
Recommended amount
The upper intake level for adults is about 4,000 IU (100 µg)/day.
Amounts are common educational ranges based on public reference values and product labels — not individual medical advice. If you have a condition, take medication, or are pregnant or breastfeeding, consult a physician or pharmacist.
When people take it
With a meal containing fat may aid absorption.
Evidence summary
Vitamin D is needed for bone health
Established evidenceIts role as an essential nutrient is established.
Who should exercise caution
Who should exercise caution
- Consult a physician if you have high blood calcium
Potential medication interactions
- Certain diuretics and heart medications
Possible side effects
- Excess intake risks high blood calcium
Upper-limit guidance
Vitamin D has an upper-limit guideline; check labels and official references.
Products & brands
FAQs
Do people in Japan need vitamin D?
Those who spend much time indoors or in low-sun seasons may watch it. If unsure, you can ask a healthcare provider.
Related articles & packs
Monthly packs
References
- Dietary Reference Intakes for Japanese (2020) — Ministry of Health, Labour and Welfare (Japan)
- Dietary Supplement Fact Sheets — NIH Office of Dietary Supplements
- Tolerable Upper Intake Levels for Vitamins and Minerals — European Food Safety Authority