Vitamin D Calculator
Estimate your recommended daily Vitamin D intake (IU) based on your weight, skin tone, latitude, and time of year.
Recommended Daily Vitamin D
Vitamin D is essential for bone health, immune function, and mood. Your needs depend on several factors:
Base recommendation by body weight:
Base IU = Weight (kg) × 40–60 IU/kg
Adjustments for:
- Skin tone — Darker skin produces less vitamin D from sunlight
- Latitude — Above 35°N or below 35°S, UVB is insufficient for much of the year
- Season — Winter months drastically reduce vitamin D synthesis
General guidelines (Endocrine Society):
- Adults: 1,500–2,000 IU/day for maintenance
- Deficiency risk: 4,000–5,000 IU/day (upper safe limit for most adults)
- Tolerable upper intake: 4,000 IU/day (standard), up to 10,000 IU under medical supervision
Risk factors for deficiency:
- Limited sun exposure or sunscreen use
- Darker skin tones
- Living above 35° latitude
- Age over 65
- Obesity
Disclaimer: Consult your doctor for blood testing and personalized dosing. This is a general estimate only.