3 ms·

What is the actual RDA for Vitamin D? There seems to be some dispute on it. Not sure who to trust.

by akulbe 6y ago

tertius 6y ago
Depends on how well you absorb it personally. For instance, if you're deficient, you need more. If you're older you need more. If you have a darker skin color you need more. It's fairly hard to get toxicity (still to be avoided). I take 50k IU per week and is good enough for me. Fat soluble so don't need it every day. But, don't take my advice on specifics...
dehrmann 6y ago
I am not a doctor, but considering it's a hormone, I'd err on the side of less.
jmalicki 6y ago
Here is one reference, others I've seen are similar: https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/ https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessiona... There is not complete consensus, but a lot of the large deltas are due to Vitamin D being fat soluble - if you are deficient, you can take far higher doses for a while and they will be stored in your liver. But if you continue to do so once you are at good levels, it can do damage: "Hypercalcemia, in turn, can lead to nausea, vomiting, muscle weakness, neuropsychiatric disturbances, pain, loss of appetite, dehydration, polyuria, excessive thirst, and kidney stones." That paper's recommendations are 600IU RDA, and that it is safe to take up to 4000IU without supervision of a doctor (i.e. regular blood tests to make sure you're not overshooting recommended blood concentration). This paper suggests up to 10000IU is safe: https://www.healthline.com/nutrition/how-much-vitamin-d-is-too-much#TOC_TITLE_HDR_4 https://www.healthline.com/nutrition/how-much-vitamin-d-is-t... and that "A daily intake ranging from 40,000–100,000 IU (1000–2500 micrograms), for one to several months, has been shown to cause toxicity in humans" (with several case reports). Apparently Dr. Fauci takes 6000IU per day. https://vitamindwiki.com/Dr.+Fauci+takes+6%2C000+IU+of+Vitamin+D+daily+%E2%80%93+Sept+2020 https://vitamindwiki.com/Dr.+Fauci+takes+6%2C000+IU+of+Vitam... While these are different, 4000IU, 6000IU, and 10000IU are well within an order of magnitude as upper limits of what you can tolerate without side effects ("upper limits" being more than RDA, but won't cause a separate medical problem) I've seen some studies say that 5000IU or 10000IU is safe, differ a little bit about the normal RDA, but there's a ton of similar ranges.
andor 6y ago
This guy focuses on prevention through proper nutrition: https://nutritionfacts.org/2011/09/12/dr-gregers-2011-optimum-nutrition-recommendations/ https://nutritionfacts.org/2011/09/12/dr-gregers-2011-optimu...

What is the actual RDA for Vitamin D? There seems to be some dispute on it. Not sure who to trust.

by akulbe 6y ago

What is the actual RDA for Vitamin D? There seems to be some dispute on it. Not sure who to trust.

Depends on how well you absorb it personally. For instance, if you're deficient, you need more. If you're older you need more. If you have a darker skin color you need more. It's fairly hard to get toxicity (still to be avoided). I take 50k IU per week and is good enough for me. Fat soluble so don't need it every day. But, don't take my advice on specifics...

dehrmann 6y ago

I am not a doctor, but considering it's a hormone, I'd err on the side of less.

jmalicki 6y ago

Here is one reference, others I've seen are similar: https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/ https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessiona... There is not complete consensus, but a lot of the large deltas are due to Vitamin D being fat soluble - if you are deficient, you can take far higher doses for a while and they will be stored in your liver. But if you continue to do so once you are at good levels, it can do damage: "Hypercalcemia, in turn, can lead to nausea, vomiting, muscle weakness, neuropsychiatric disturbances, pain, loss of appetite, dehydration, polyuria, excessive thirst, and kidney stones." That paper's recommendations are 600IU RDA, and that it is safe to take up to 4000IU without supervision of a doctor (i.e. regular blood tests to make sure you're not overshooting recommended blood concentration). This paper suggests up to 10000IU is safe: https://www.healthline.com/nutrition/how-much-vitamin-d-is-too-much#TOC_TITLE_HDR_4 https://www.healthline.com/nutrition/how-much-vitamin-d-is-t... and that "A daily intake ranging from 40,000–100,000 IU (1000–2500 micrograms), for one to several months, has been shown to cause toxicity in humans" (with several case reports). Apparently Dr. Fauci takes 6000IU per day. https://vitamindwiki.com/Dr.+Fauci+takes+6%2C000+IU+of+Vitamin+D+daily+%E2%80%93+Sept+2020 https://vitamindwiki.com/Dr.+Fauci+takes+6%2C000+IU+of+Vitam... While these are different, 4000IU, 6000IU, and 10000IU are well within an order of magnitude as upper limits of what you can tolerate without side effects ("upper limits" being more than RDA, but won't cause a separate medical problem) I've seen some studies say that 5000IU or 10000IU is safe, differ a little bit about the normal RDA, but there's a ton of similar ranges.

andor 6y ago

This guy focuses on prevention through proper nutrition: https://nutritionfacts.org/2011/09/12/dr-gregers-2011-optimum-nutrition-recommendations/ https://nutritionfacts.org/2011/09/12/dr-gregers-2011-optimu...