As we move into flu season many of us are thinking of ways to boost our immunity. As we’ve discussed here before, people often choose a flu shot while also taking more elderberry, Andrographis and/or medicinal mushrooms.
But there’s one very important vitamin you may have overlooked: Vitamin D. You probably associate Vitamin D with building strong bones, which is accurate, but it does so much more.
Studies show that having low levels of vitamin D increases your risk of having poor upper respiratory function and getting upper respiratory infections. An Australian study of 5,000 baby boomers found that low levels of vitamin D were associated with respiratory conditions such as asthma, bronchitis, wheezing, and chest tightness. Higher levels of vitamin D were associated with better lung function overall. Another study showed giving children 1,200 IU of vitamin D a day for four months during winter reduced their risk of getting the flu by more than 40 percent. Meta-analysis of 11 placebo-controlled trials involving 5,660 subjects concluded that those taking a daily dose of vitamin D had half the risk of developing an upper respiratory infection.
Clearly, taking vitamin D at this time of year can be a good idea. But protecting your lung function isn’t the only thing vitamin D can do. Studies show it can:
That’s because vitamin D is really a hormone, a chemical messenger with wide effects on various parts of the body, including the immune system. There are vitamin D receptors in nearly every cell. It’s primarily known for being involved in mineral metabolism and bone growth, especially via its ability to facilitate intestinal absorption of calcium. But it also modulates cell growth, immune function, neuromuscular function, and it reduces inflammation, giving it body-wide effects.
Little wonder then, that vitamin D deficiency is associated with:
There’s really no way to know your vitamin D levels without getting a lab test. That’s a good idea, because while low levels put you at risk for several unwanted health conditions, levels too high can cause adverse effects, too. Abnormally high levels of vitamin D are associated with a build-up of calcium in the blood, causing digestive upset, fatigue, dizziness, confusion, excessive thirst, and frequent urination. Vitamin D is fat soluble, so when you supplement it builds up over time. It’s prudent to get a lab test before you supplement and again after you’ve been taking it for awhile. Everyone absorbs differently, so there’s no one-size-fits-all appropriate dose. Test your blood levels, and supplement accordingly.