Serum Level vs Intake Charts
One of the most common questions we receive at GrassrootsHealth after an individual has tested their vitamin D is “How much vitamin D should I take to get my levels up?”
Based on a plot of 25(OH)D values as a function of reported vitamin D intake amounts for 7,324 D*action participants, a calculation was produced to estimate the additional daily vitamin D intake needed for 90% of adults to reach a chosen target 25(OH)D serum level (age 18 years and older, weighing an average of 150 lbs). The charts referenced here can be used as a tool to calculate how much additional supplemental vitamin D is needed to get 90% of individuals from an initial vitamin D serum level to a desired vitamin D serum level.
Example: With a starting serum level of 20 ng/ml an additional intake of approximately 5,000 IU/day would be sufficient for 90% of adults (age 18 years and older, weighing 150 lbs) to achieve a serum level of at least 40 ng/ml (100 nmol/L).
Four versions of this chart are available in the download:
- Change in Serum Level Based on Intake (IU/day) for 90% of Adults – these charts show calculations based on an average weight of 150 lbs
- Available in ng/ml and nmol/L
- Change in Serum Level Based on Intake (IU/lb and IU/kg) for 90% of Adults – these charts show how to calculate using an individual’s weight
- ng/ml and nmol/L
You may also use our D*calculator for the same calculations based on weight, starting serum level, and target serum level.
Dimensions: 11 x 8.5 inches