Free Vitamin D Needs Calculator
Estimate your daily vitamin D requirement based on age, sun exposure, and body weight.
years
lbs
Recommended Vitamin D
680 IU/day
In Micrograms17.0 mcg
Recommended Vitamin D vs Age
Vitamin D Requirement Estimation
Vitamin D requirements vary by age, body weight, and sun exposure. The RDA is 600 IU for ages 1-70 and 800 IU for those over 70.
Adjusted Formula
Vitamin D (IU) = Base IU x Sun Factor x (Weight / 150)
This adjusts the base RDA for body size and sun exposure, since vitamin D is produced in the skin when exposed to sunlight.
Example Calculation
A 35-year-old, 170 lbs, with moderate sun exposure.
- 01Base IU (age <= 70) = 600
- 02Adjusted = 600 x 1.0 x (170 / 150)
- 03= 600 x 1.133 = 680 IU/day
- 04In mcg = 680 / 40 = 17.0 mcg
Frequently Asked Questions
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