Sunlight and vitamin D?

Dr. Rhonda Patrick emphasizes the importance of UVB radiation from sunlight as the primary source of vitamin D, noting that it's difficult to obtain sufficient vitamin D from dietary sources alone. The skin synthesizes vitamin D3 when exposed to UVB rays, but factors like geographic location, season, sunscreen use, and melanin levels impact production. For instance, in northern latitudes during winter, UVB radiation is minimal, making vitamin D synthesis challenging 1.

Patrick also highlights the impact of body fat and age on vitamin D synthesis and bioavailability. Older individuals and those with higher body fat require more vitamin D due to decreased efficiency in production and bioavailability 2. She states that vitamin D is a steroid hormone regulating around 5% of the human genome, making its adequate levels crucial for overall health 2.

She also stresses the need for balancing sun exposure with skin protection. While sunscreen is necessary to prevent skin cancer, it can block UVB radiation and consequently vitamin D production. In regions with high UVB radiation, like Australia, supplementation is recommended along with sun protection 2.

Moreover, Patrick suggests that most people would benefit from vitamin D supplementation, especially those who don't get sufficient sun exposure or have dietary restrictions. A safe daily dose ranges from 1000 to 5000 IU, depending on individual needs and genetic factors 3 4.

Ultimately, Dr. Patrick underscores the need for adequate vitamin D levels (40-60 ng/ml) for optimal health, achievable through a combination of sun exposure and supplementation 5.