Vitamin D Benefits
In addition to keeping bones strong by helping the body absorb calcium, vitamin D has been associated with a decreased risk of a number of conditions, such as osteoporosis, hypertension and cancer. However, other research suggests that vitamin D supplements may not be a panacea.
Thomas said it is safe to assume that vitamin D’s benefits are marginal at best, though researchers cannot know for sure until large, randomized studies are conducted and their results analyzed.
“For many of the nutrients maintaining health or treating disease, the effect at best is going to be very small,” he said.
Another issue in studies that associate low vitamin D levels with sickness is a lack of causality, Rosen said. Sick people may have lower vitamin D levels due to their illness, not necessarily the other way around.
How Much Vitamin D Is Enough?
To attain the 20 ng/mL blood serum level of the vitamin D biomarker, the National Institutes of Health recommends an average daily amount that varies from 400 to 800 International Units of the vitamin, depending on one’s age.
Thomas said there is “a range in which you can play,” from the mid-hundreds to around 4,000 units of the vitamin per day, the safe upper limit according to the National Academy of Medicine.
Vitamin D Deficiency
Symptoms of vitamin D deficiency can include bone and muscle weakness, increasing the risk of fractures and falls for older adults. In children, deficiency can lead to a softening of the bones known as rickets. After scientists discovered rickets’ link to vitamin D deficiency in the 1900s, they began fortifying foods with the vitamin, and the condition is now considered a rare disease by the National Institutes of Health.
For most people, vitamin D deficiency doesn’t develop out of the blue, Thomas said. People who rarely go outside or are extremely picky eaters might be at risk, but for the majority of people, what they’re doing is fine, he added.
Despite this, Rosen said that 10 percent or more of people who come in for routine checkups are tested for vitamin D deficiency, which is completely unnecessary if they do not display any symptoms, he said.
“Doctors want to measure something,” he said, adding that finding a serum level below adequacy and prescribing a pill is a quick fix that can make the doctor feel successful. “If we didn’t have supplements, I don’t think we would be measuring vitamin D.”
Written by Maddie Bender for CNN.
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