The sunshine vitamin is probably one of the most commonly deficient vitamins I encounter in blood tests on my patients. We simply don’t get enough sun, nor foods rich in vitamin D. These foods include salmon, cod liver oil, and matsutake mushrooms, among others. But it’s perhaps most important to get vitamin D through safe sun exposure.
Why is it so crucial? Vitamin D regulates over 200 genes, and plays a critical role in supporting healthy gut permeability, as well as a responsive, well-coordinated immune system. I typically take 2,000 IU through vitamin D supplements in the summer months, and increase it to 5,000 IU daily during cold and flu season.