You’ve tested your vitamin D recently and levels were normal or high (as a fat soluble vitamin, it is possible to overdose on)
As somebody who hasn’t tested my vitamin D level and doesn’t know how (I assume this isn’t something you can easily do with standard household materials?) and is worried about the possibility of overdose if I suddenly start supplementing—how should I calibrate on my “likely current vitamin D level” and what level of supplementation is safe?
You can get vitamin D from sunlight. You can’t overdose this way, but you could get a sunburn, which has its own problems. An app like dminder can help you time your sun exposure.
As somebody who hasn’t tested my vitamin D level and doesn’t know how (I assume this isn’t something you can easily do with standard household materials?) and is worried about the possibility of overdose if I suddenly start supplementing—how should I calibrate on my “likely current vitamin D level” and what level of supplementation is safe?
FWIW, I started taking Vitamin D without measuring my blood levels after reading https://www.gwern.net/Longevity#vitamin-d . I take 2000 IU/day; the NIH site says the “tolerable upper intake level” is 4,000 IU, so I think I have pretty good margins. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional
OOPS! I misread Chris Masterjohn’s advice. He recommends NO vitamin D supplements until the coronovirus threat is reduced.
You can get vitamin D from sunlight. You can’t overdose this way, but you could get a sunburn, which has its own problems. An app like dminder can help you time your sun exposure.
find others in your area who have similar sun exposure to you, and see if any of them were tested
ask a local doctor about local levels
see the maps/prevalences here:
https://docs.google.com/document/d/1q5IH2hGjjdPi-vcs4zOBlArgFJ9iSDdZVoceevUPI9c