Apr 20, 2024 03:18 AM
Even daily doses of 1,000 IUs have afflicted some seniors with kidney stones, who already had diminished kidney function.
- - - - - - - - - - -
Should you take vitamin D? Here’s the science
https://knowablemagazine.org/content/art...d-how-much
EXCERPT: . . . Since 2010, the National Academy of Medicine has recommended relatively modest daily doses: 400 international units (IUs) for babies, 600 IUs for everyone up to age 70 and 800 IUs for older people. These doses are designed to achieve levels of 20 nanograms per milliliter — more than enough to avoid severe deficiencies — for otherwise healthy people in the United States.
Most people should be able to get these doses through brief sun exposure, says John Christopher Gallagher, an endocrinologist at Creighton University in Omaha, Nebraska. Measuring vitamin D production in the skin is not an exact science, but five to 10 minutes’ daily exposure without sunblock of just the face, neck, hands and arms should do the trick in the sunnier months, even in temperate places like Boston. While it’s entirely possible to get enough vitamin D this way, the official stance of the American Academy of Dermatology is to not get vitamin D from sun exposure.
Fortified dairy products and other foods will also provide enough. Foods that naturally contain vitamin D, such as fatty fish, egg yolks, red meat, liver and irradiated or sun-dried mushrooms, which are especially rich in vitamin D due to their increased exposure to UV light, can also help. “If you’re out and about and you have sun exposure during some months of the year,” Gallagher says, “you probably get plenty of vitamin D.” That’s especially true if you have enough dairy in your diet.
Generally, people need supplements only when they’re not likely to get enough from natural or dietary sources, health experts say. Deficiency-prone populations include breastfed infants who don’t get fortified formula, elderly people (whose skin makes vitamin D less efficiently) and pregnant women. People with dark skin tones should also take care to get sufficient vitamin D, because melanin pigmentation in the skin blocks UV light. People in northern latitudes like England “should all take a supplement during the winter,” adds nutritional scientist Susan Lanham-New of the University of Surrey in the UK, although that’s less important in places like the United States that have food fortification.
Experts worry that it’s often the people already getting enough vitamin D through diet and lifestyle who are the most likely to take supplements, Christakos notes. Meanwhile, communities who need vitamin D supplements the most might not realize their need and may have read news reports suggesting that the supplements aren’t necessary.
That’s an especially dangerous message in countries where deficiencies are common — for instance in the UK, where physicians still see children with deficiency-related ailments, says Martin Hewison, a molecular endocrinologist at the University of Birmingham in that country. One of his UK colleagues is struggling to persuade some of her vitamin D-deficient patients to take supplements because they believe it is a waste of time.
But avoid the high doses — of 5,000, 10,000 or 20,000 IUs, or even higher — that can be found in drugstores or online, stresses JoAnn Manson, an endocrinologist and epidemiologist at Brigham and Women’s Hospital and Harvard Medical School. Too much vitamin D, even when taken occasionally, can sometimes cause bone health to deteriorate and lead to an overdose of calcium in the blood and urine, resulting in nausea and even kidney failure. There are reports of people in the UK and US ending up in the hospital after taking excessive doses... (MORE - details)
- - - - - - - - - - -
Should you take vitamin D? Here’s the science
https://knowablemagazine.org/content/art...d-how-much
EXCERPT: . . . Since 2010, the National Academy of Medicine has recommended relatively modest daily doses: 400 international units (IUs) for babies, 600 IUs for everyone up to age 70 and 800 IUs for older people. These doses are designed to achieve levels of 20 nanograms per milliliter — more than enough to avoid severe deficiencies — for otherwise healthy people in the United States.
Most people should be able to get these doses through brief sun exposure, says John Christopher Gallagher, an endocrinologist at Creighton University in Omaha, Nebraska. Measuring vitamin D production in the skin is not an exact science, but five to 10 minutes’ daily exposure without sunblock of just the face, neck, hands and arms should do the trick in the sunnier months, even in temperate places like Boston. While it’s entirely possible to get enough vitamin D this way, the official stance of the American Academy of Dermatology is to not get vitamin D from sun exposure.
Fortified dairy products and other foods will also provide enough. Foods that naturally contain vitamin D, such as fatty fish, egg yolks, red meat, liver and irradiated or sun-dried mushrooms, which are especially rich in vitamin D due to their increased exposure to UV light, can also help. “If you’re out and about and you have sun exposure during some months of the year,” Gallagher says, “you probably get plenty of vitamin D.” That’s especially true if you have enough dairy in your diet.
Generally, people need supplements only when they’re not likely to get enough from natural or dietary sources, health experts say. Deficiency-prone populations include breastfed infants who don’t get fortified formula, elderly people (whose skin makes vitamin D less efficiently) and pregnant women. People with dark skin tones should also take care to get sufficient vitamin D, because melanin pigmentation in the skin blocks UV light. People in northern latitudes like England “should all take a supplement during the winter,” adds nutritional scientist Susan Lanham-New of the University of Surrey in the UK, although that’s less important in places like the United States that have food fortification.
Experts worry that it’s often the people already getting enough vitamin D through diet and lifestyle who are the most likely to take supplements, Christakos notes. Meanwhile, communities who need vitamin D supplements the most might not realize their need and may have read news reports suggesting that the supplements aren’t necessary.
That’s an especially dangerous message in countries where deficiencies are common — for instance in the UK, where physicians still see children with deficiency-related ailments, says Martin Hewison, a molecular endocrinologist at the University of Birmingham in that country. One of his UK colleagues is struggling to persuade some of her vitamin D-deficient patients to take supplements because they believe it is a waste of time.
But avoid the high doses — of 5,000, 10,000 or 20,000 IUs, or even higher — that can be found in drugstores or online, stresses JoAnn Manson, an endocrinologist and epidemiologist at Brigham and Women’s Hospital and Harvard Medical School. Too much vitamin D, even when taken occasionally, can sometimes cause bone health to deteriorate and lead to an overdose of calcium in the blood and urine, resulting in nausea and even kidney failure. There are reports of people in the UK and US ending up in the hospital after taking excessive doses... (MORE - details)
