A few years ago, I broke three bones in my feet. The injuries were out of the blue — I didn’t kick a rock or do anything irregular. My doctors determined that I wasn’t absorbing a very crucial nutrient for bone health — vitamin D. I spent the better part of the year in a walking boot and it took me six months to raise my vitamin D levels, even on megadose vitamins. The ordeal led me to wonder — what caused my vitamin D deficiency? And how could I have prevented it?
Causes Of Vitamin D Deficiency
Unlike many other nutrients in our diets, vitamin D comes from two major sources — our diets and from sun exposure. If you have a limited diet and minimal sun exposure, you’re likely to find yourself falling below the recommended threshold of between 400 and 1000 iu of vitamin D per day.
Because we lead mostly indoor lives, 40 percent of Americans are vitamin D deficient.
Failure to consume food rich in vitamin D or to get out in the sun aren’t the only reasons people experience this problem, though. Many people with digestive problems like Celiac disease, Crohn’s, and cystic fibrosis struggle to absorb vitamin D from the food they eat. People with these conditions may need to consume much higher levels of vitamin D or focus on light exposure in order to reach optimum levels.
Another common and unavoidable reason that some people experience vitamin D deficiencies is simply having darker skin. Greater melanin levels simply make the body less receptive to vitamin D, and older adults are especially vulnerable to poor absorption.
What About Sunscreen?
When it’s sunny outside, it should be much easier to absorb vitamin D, right? If you’re using sunscreen to protect your skin from harmful UV rays, are you missing out on that vitamin D?
Vitamin D production is triggered by UVB waves interacting with a protein in the skin, but UVB is also responsible for most cancer-causing skin damage, so sunscreens are designed to block this part of the light spectrum.
Luckily for your vitamin D levels, there’s always a gap in this protection, meaning about 2 to 7 percent of UVB rays reach your skin, even when you use very high SPF sunscreen. Our skin is very efficient at converting sun into vitamin D, this light exposure coupled with any dietary vitamin D should be enough to equip your body with its ideal vitamin D levels.
Keep wearing your sunblock, even if you’re struggling with vitamin D deficiency.
Even though sunscreen blocks most UVB, studies have consistently shown that even those who wear daily, broad-spectrum sunscreen can maintain normal vitamin D levels.
Should I Take Vitamin D Supplements?
It took me six months of vitamin D supplements to reach an acceptable level, but my case was also pretty extreme since it resulted in broken bones. But does the average case of vitamin D deficiency call for supplements?
While it’s almost always better to get your vitamins from food, which have better bioavailability — meaning they’re absorbed more readily, there are a few factors that can help you determine whether supplements are the right choice for you. It all starts in the doctor’s office.
If you have a vitamin D deficiency, your doctor may prescribe you a high strength supplement to help raise your blood levels. You should take these, and your doctor will check your vitamin D levels at intervals to see if you’re absorbing them properly.
Beware of taking supplements if your levels are in the normal range, though, because an excess of the vitamin can be toxic, causing nausea and vomiting, kidney problems, and high blood calcium levels.
Foods Rich With Vitamin D
Rather than taking supplements for mild vitamin D deficiency, the best approach is to add more vitamin D rich foods to your diet. There are plenty of delicious foods packed with this nutrient, and one trend you’ll quickly notice is that most of them are also high in good fats, like omega-3s.
Salmon, Herring, and Sardines
Cold water fish are packed with vitamin D and it contains an ideal proportion to the fat that helps your body absorb it. A single serving of these types of fish will put you over your recommended daily intake (RDI) of this crucial vitamin, making a supplement entirely unnecessary. Bonus: salmon is also a superfood.
If you’ve looked at the cow’s milk in your refrigerator recently, you may have noticed some labels. Across the board, milk is fortified with vitamin D since it contains fat to aid absorption, as well as calcium, which along with vitamin D is important for bone health. A cup of whole milk is about 20 percent of your RDI, but it’s also a one-stop shop when it comes to osteoporosis prevention.
What should you do if your lactose intolerant? Luckily, soy milk also contains about 17 percent of your daily vitamin D, so you can substitute that for cow’s milk. Many brands of almond milk are also fortified with vitamin D, though it isn’t naturally occurring.
Most of the time, we recommend vegetables when trying to manage nutritional deficiencies, but as it turns out mushrooms are the only plant that contains vitamin D. It’s typically not much (3 percent RDI in four shitake mushrooms), but you will find a little in your favorite fungi, so you can cook up a few if you need to grab a little more vitamin D in your meal plan.
Vitamin D deficiencies may be common, but for most people, they’re easily remediable. Just whip up some tuna salad for lunch, grab a glass of milk, or take a break in the backyard (protected by sunscreen, of course). Though in recent years most of us have begun spending too much time inside to maximize vitamin D production, it only takes a few minutes to fill up on sunshine.