What is the optimal vitamin D level?

Dr. Rhonda Patrick suggests that the optimal vitamin D level in the blood is between 40 to 60 nanograms per milliliter. This range is associated with the lowest all-cause mortality based on various studies, including meta-analyses of all-cause mortality studies spanning several decades 1 2 3.

She emphasizes the importance of regular blood tests to monitor and adjust vitamin D levels, as individual requirements can vary due to factors like genetics, age, skin pigmentation, and sun exposure 4 1. Moreover, while the upper safe intake level for vitamin D is often set at 4000 IU per day, she notes that some people might require higher doses to achieve optimal blood levels 3.