Is there an optimal daily dose of vitamin D for immune function? | Roger Seheult

Summary

This transcript discusses the relationship between vitamin D levels and health outcomes, particularly the increased risk of SARS-CoV-2 positivity when levels fall below 50 nanograms per milliliter. It highlights a meta-analysis linking vitamin D to all-cause mortality, suggesting an optimal range of 40 to 60 or 70 nanograms per milliliter. The conversation also touches on the safety of vitamin D supplementation, noting its low toxicity compared to other fat-soluble vitamins, and the nonlinear response of vitamin D levels to supplementation, where higher doses have diminishing returns.

Takeaways

• 🌞 The storage form of vitamin D, 25-hydroxyvitamin D, is crucial for health, with levels below 50 nanograms per milliliter linked to increased SARS-CoV-2 positivity rates.
• 📉 Current vitamin D level recommendations are primarily based on its role in bone metabolism, but there may be different optimal levels for immunological functions related to COVID-19.
• 🔍 A meta-analysis of studies from the 1960s to 2013 showed an association between vitamin D blood levels and all-cause mortality, with an optimal range between 40 to 60 or 70 nanograms per milliliter.
• 💊 The upper tolerable intake level for vitamin D, as set by the Institute of Medicine, is 4000 IUs per day, highlighting the importance of not exceeding this amount.
• 🚫 Vitamin D is considered the least toxic fat-soluble vitamin, with a study of 20,000 people showing minimal risk of hypercalcemia even at high supplementation levels.
• 📈 The relationship between vitamin D supplementation and blood levels is nonlinear, with the first 1000 IUs having a more significant impact on levels than higher doses.
• 🧬 The increase in vitamin D levels from supplementation diminishes as the dosage increases, suggesting a saturation point for vitamin D receptors in the body.
• 🧬 Polish scientists studied the Mayo Clinic's database and found only one case of hypercalcemia out of 20,000 people, indicating a very low risk of toxicity from vitamin D supplementation.
• 📚 A study mentioned by Dr. Patrick found no toxic effects from long-term supplementation with 10,000 IUs of vitamin D per day.
• 🌐 The transcript discusses the importance of vitamin D in both endocrinological and immunological contexts, emphasizing its multifaceted role in human health.
• 📉 The transcript suggests that maintaining adequate vitamin D levels could be beneficial for overall health and potentially for reducing the risk of severe outcomes from COVID-19.

Q & A

What is the primary form of vitamin D that is stored in the body?

The primary storage form of vitamin D is 25-hydroxyvitamin D.

What is the significance of vitamin D levels dropping below 50 nanograms per milliliter?

When vitamin D levels drop below 50 nanograms per milliliter, there is an observed increase in SARS-CoV-2 positivity rates.

How are the recommended vitamin D levels related to bone metabolism?

The recommended vitamin D levels are largely based on their endocrinological function with bone metabolism, although their exact value for immunological functioning or COVID is not yet known.

What did the associative studies involving 191,000 people suggest about vitamin D levels and SARS-CoV-2 rates?

The associative studies indicated that SARS-CoV-2 rates started to increase once vitamin D levels dropped below 50 nanograms per milliliter.

What is the 'sweet spot' for vitamin D levels in terms of all-cause mortality according to the meta-analysis?

The meta-analysis found that vitamin D levels between 40 to 60 or 70 nanograms per milliliter were associated with the lowest all-cause mortality.

What is the upper tolerable intake of vitamin D as set by the Institute of Medicine?

The upper tolerable intake of vitamin D, as set by the Institute of Medicine, is 4000 IUs (International Units) per day.

Why is vitamin D considered the least toxic fat-soluble vitamin?

Vitamin D is considered the least toxic fat-soluble vitamin because of its low toxicity profile; a study involving 20,000 people found only one case of hypercalcemia even with supplementation up to 55,000 units a day.

What was the case of hypercalcemia found in the study involving the Mayo Clinic's database?

In the study, one person out of 20,000 developed hypercalcemia with a vitamin D level in the 200-300 nanograms per milliliter range, which is considered very high.

What is the observed long-term effect of supplementing with 10,000 IUs of vitamin D daily?

Long-term supplementation with 10,000 IUs of vitamin D daily showed no toxic effects, as mentioned in a study that Dr. Patrick referred to.

How does the increase in vitamin D supplementation relate to the increase in nanograms per milliliter?

The increase in nanograms per milliliter is not linear with supplementation. The first 1000 units of supplementation increase levels by about 4.8 to 5 nanograms per milliliter, whereas at higher doses like 15,000 to 30,000 units, each additional 1000 units results in a much smaller increase.

What does the nonlinear relationship between vitamin D supplementation and serum levels suggest about the body's response?

The nonlinear relationship suggests that as supplementation increases, the body's ability to absorb additional vitamin D decreases, possibly due to receptor saturation, although this is not definitively proven.