How Do You Know If You Have A Vitamin D Deficiency, And How Do You Treat It?

Vitamin D is probably significant less likely to be on your radar than, say, iron, calcium, or vitamin C — but if you aren't sure whether you could possibly be deficient in this important vitamin, you should know that the answer is a definitive "yes". Research shows that a shocking 41.6 percent of Americans have low vitamin D levels, you see. Your risk of being deficient rises to an even more mind-blowing 82.1 percent if you are black, with Latinx folks having a 69.2 percent risk of suffering from a vitamin D deficiency. 

In addition, you're more likely to have low vitamin D levels if you're obese or have health conditions like high cholesterol or high blood pressure, or live in a nursing home, and people who never drink milk also develop vitamin D deficiencies at higher rates. 

What is vitamin D, and why should you check if you are deficient?

Vitamin D is a vital vitamin that helps you keep your bones and teeth strong, your muscles healthy, and the inflammatory processes in your body under control. It comes in two main forms — vitamin D2 and vitamin D3. While the differences between the two are significant, the main things you should take away from this quick read is that vitamin D2 comes from plant, yeast, and mold sources and you can get vitamin D3 from animal sources or by spending time in the sun. That is because your skin makes its own vitamin D3 when you are exposed to UV rays. Overall, vitamin D3 is more effective at raising your overall vitamin D levels than vitamin D2 is.

However, eating a nice, vitamin D rich, meal (think salmon or beef with mushrooms, for instance) or spending the whole day in the sun won't set you up for a very long time. Vitamin D only has a short lifespan; after a day or two, your body will metabolize it or store it within your fat cells, where it will be inaccessible. To make sure you are not deficient in vitamin D, your body needs a constant input. 

What symptoms might indicate a vitamin D deficiency?

You may have heard that a vitamin D deficiency can cause rickets and bone pain, but it can cause a whole range of other symptoms, too. While the symptoms of a serious vitamin D deficiency are not nearly as apparent in adults as they are in children, they can include:

• Muscle weakness, cramps, or pain
• Overall fatigue
• A decrease in mental power — especially in older adults
• Mood swings and irritability, and in severe cases even depression
• Due to the role vitamin D plays in maintaining a healthy immune system, a higher risk of developing certain respiratory infections, including COVID-19. 

How can you find out if you are vitamin D deficient?

Pregnant women, older adults (over 65), those with chronic medical conditions, and people who don't spend much time in the sun should especially consider getting a vitamin D test, and children, too, should be tested. If you are aware that you do not consume many vitamin D rich foods, which would include fatty fish, beef liver, mushrooms, cheeses, other dairy products, and foods fortified with the vitamin (such as cereals), it may be time to get a test as well.

While it is always a good idea to have a vitamin D test, and find out whether you are deficient or not, here's another thing to consider. The same groups that have been found to be at risk of being deficient are already advised to routinely take supplements, even without being tested. The recommended dose in this case is 10 milligrams (or 400 IU) a day, especially during the sun-starved winter months. You may, of course, also be able to make sure you get your daily recommended dose through sunlight and diet alone.

Considering that vitamin D plays an incredibly important role in nearly every aspect of your general health and functioning — from your bone and muscle health to your risk of cancer, and from your risk of infection to your cognitive abilities — starting supplementation immediately may well be the right choice for you. Especially in the age of COVID, it could make an immense difference. 

On the other hand, it's also important to know that getting too much vitamin D can also be bad for you — people who consume immense quantifies and also spend a lot of time exposed to UV rays may develop signs like nausea, vomiting, constipation, weight loss, and poor appetite to indicate that they are experiencing vitamin D toxicity. Because you don't want to risk that, it is best to be tested for a vitamin D deficiency before you start to take supplements.