25 Hydroxyvitamin D calculator for seasonal adjustment

Single measurements of 25-hydroxyvitamin D (vitamin D) do not accurately reflect long-term exposure due to seasonal variation in the intensity of sunlight. Use this calculator to estimate your annual mean concentration of vitamin D based on a single measurement and the time of year that measurement was taken. Questions or comments? Email Ian de Boer.

Please input your information

Month of measurement:
25(OH)D Value:

Your annual mean 25(OH)D value is 28.28 ng/mL

Your minimum 25(OH)D (in February) value is 24.6 ng/mL

Your maximum 25(OH)D (in August) value is 31.97 ng/mL