If you live in the Northern Hemisphere, unless you stroll outside three times a week wearing a tank top and shorts, you’re probably not getting enough Vitamin D.
Why should you care? Because broken bones hurt.
“Vitamin D promotes calcium absorption,” said Dr. Kevin Ly, Geisinger Elysburg – Community Medicine. “It also helps to maintain normal calcium and phosphate concentrations, which are important for bone health. Vitamin D helps protect older adults from osteoporosis.”
“When you see individuals that have poor Vitamin D, where they’re either deficient or they don’t have any Vitamin D at all, then you start to see the breakdown in the bone formation,” said Dr. Marcus Powers, primary care physician at UPMC Lock Haven.
Vitamin D is a fat soluble vitamin, which means it will build up in the body. So therefore, it’s possible to get too much Vitamin D or have a deficiency, said Dr. Thomas Krebs, Family Medicine of Evangelical – Middleburg.
“We need this vitamin for bone health, but also for immune function,” he said. “It’s very important for the immune system.”
He referred to two studies that demonstrate Vitamin D’s benefit in helping our immune system. A 2018 study showed that the higher the level of Vitamin D in pregnant women, the fewer respiratory infections their children had. Fortunately, prenatal vitamins always have Vitamin D in them.
The second study, in August, 2020, found that 50- to 75-year-olds with Vitamin D deficiency had a much higher risk of dying from respiratory infections compared with those with a much higher level of Vitamin D.
The sunshine vitaminVitamin D is called the sunshine vitamin because it’s produced by the body in response to sun exposure
“It comes down to spending time outside,” Powers said. “Sunlight creates an inactive form of Vitamin D where it goes through a lot of enzymatic changes in the liver and kidneys to make it the active Vitamin D that the body can use.”
Sunlight is really important as long as people can avoid crossing that boundary and start to develop a sunburn, which can increase chances of skin cancer, Powers said. But that’s a tough balance to strike.
“In regards to the sunlight, there really isn’t a specific recommendation,” he said. “And that’s because it’s really difficult to predict on an individual basis because it all depends on the skin type, it depends on the latitude of where you live on the planet, it depends on the season and the time of day. That’s why it’s really hard to say, ‘Okay, you have to spend 30 minutes outside in the sun for you to get the perfect amount of Vitamin D.’ That’s really hard to tell because with each individual it varies quite a bit.”
“The length of time is dependent on the region of the country or world and also skin color,” Ly said. “Sun exposure should be balanced with the risk of skin cancer, as UV radiation is a preventable cause of skin cancer.”
Krebs agreed, saying that to get a sufficient amount of Vitamin D, people would need to expose at least a third of their body to the sun for 30 minutes, three times a week – a scenario akin to someone wearing a tank top and shorts for a half-hour, three times a week, year-round.
“In our area of the United States, that just doesn’t happen,” he said. “If you’re a lifeguard, then you don’t need Vitamin D. If you’re a landscaper, you don’t need Vitamin D. If you’re working at WoodMode, or the Middleswarth chip factory, or in a medical clinic or anyplace you’re indoors all day, you’re not getting sun exposure. Therefore, most of the patients I treat are deficient in Vitamin D.”
Sunscreens decrease the amount of Vitamin D the body produces, but they don’t eliminate it, he said.
Supplements helpThe recommended dietary allowance of vitamin D for adults is 600 IU (international units) a day, Ly said. For individuals 70 years or older, it’s 800 IU daily.
It can be difficult to get enough Vitamin D through diet. Eggs contain 41 IU each. Sockeye salmon has a whopping 440 units, but it’s expensive. Cold-water fish like tuna, salmon and trout all have Vitamin D, as do mushrooms and fatty fish liver … not exactly the stuff of a typical, everyday diet.
In the United States, foods fortified with a synthetic kind of Vitamin D include milk, infant formula and breakfast cereals, Powers said.
“So as long as people eat cereal and drink milk, it should be in those products,” he said.
Nevertheless, diet alone does not usually provide enough Vitamin D to maintain sufficient levels.
“Most of the people I test are low,” Krebs said. “Typically I recommend 1,000 to 2,000 IU daily during the winter months. This is what I’ve found it takes to get people up to normal.”
Although rare, it is possible to get too much Vitamin D. If you take a mega dose for months, you can get Vitamin D toxicity, which could lead to a very high calcium level, pancreatitis or kidney damage, Krebs said.
“If you’re going to be taking higher doses,” he said, “definitely get your levels checked.”
