What's Rhonda Patrick's guidance on Vitamin D supplementation?

Dr. Rhonda Patrick recommends a daily dose of 5000 IUs of vitamin D3. She notes that this dosage maintains her vitamin D levels at around 50 nanograms per milliliter. According to her, it is extremely difficult to develop hypercalcemia, the major concern with high levels of vitamin D3 supplementation, without ingesting several hundred thousand IUs over an extended period. The upper tolerable limit set by the Institute of Medicine is 4000 IUs, which is considered safe. However, measurement of vitamin D levels before and after supplementation is essential to adjust the dose properly, especially for those with single nucleotide polymorphisms (SNPs) that affect vitamin D metabolism 1.

She emphasizes the importance of having one's vitamin D levels tested. Dr. Patrick explains, for instance, that typically, taking 1000 IUs of vitamin D will raise blood levels by around 5 nanograms per milliliter. To achieve sufficient levels, it's essential to know one's current vitamin D levels and tailor supplementation accordingly 2.

Regarding vitamin D sources, she mentions that while vitamin D2 can be found in fortified foods like milk and fatty fish contain certain levels of vitamin D, sunlight exposure is a significant natural source for producing vitamin D3 in our skin 3.

Additionally, Dr. Patrick highlights the importance of vitamin D beyond just bone health, mentioning that it is a steroid hormone, regulating gene expression, impacting more than 5% of the protein-encoding human genome, and discussing its role in aging 4 5.

She also discusses the increased need for vitamin D supplementation due to factors such as skin pigmentation and modern indoor lifestyles, noting that about 70% of the US population has inadequate vitamin D levels 6. Dr. Patrick advocates for the proactive measurement and management of vitamin D levels to promote overall health and longevity.