If You Feel Exhausted All The Time, Here's What Might Be Missing From Your Diet

Staying healthy is rarely ever a cut-and-dry situation. From your mind, to your body, to your soul, it can be difficult to stay on top of all of the different aspects of your well-being, given that some of these things can't always be seen from the outside, or might not radically change your life, even if they merit your attention. For example, you might not recognize the subtle signs you need more vitamin D at first, even though this nutrient really is a super important aspect of your health.

Now, aside from knowing that vitamin D is something that comes from sources like sunlight and orange juice, what else do you really know about it? Maybe not that much? Same, girl, so let's get technical for a second: According to the National Institutes of Health's Office of Dietary Supplements (ODS), "vitamin D is a fat-soluble vitamin" that is known primarily for keeping your bones strong by promoting calcium absorption in the body. Unfortunately, the ODS also notes how few foods vitamin D appears within naturally, which could explain, at least partially, why almost half of Americans were found to have a vitamin D deficiency in a 2011 study.

Vitamin D most often reaches the body not through consumption of food, but through the rays of the sun. More specifically, the ODS explains that vitamin D is produced by your own body when "ultraviolet rays from sunlight strike the skin and trigger vitamin D synthesis." Given that vitamin D is often associated with sunlight, and probably doesn't play a central role in your grocery-shopping trips each week, you might have no clue whatsoever whether you, personally, are deficient in vitamin D.

According to Healthline, one of the main signs of a vitamin D deficiency is bodily aches and pains.

This is tough, though, since aches and pains can obviously be symptoms of so many different types of illnesses, or they could just mean nothing at all, at least in a long-term sense. But other symptoms could cumulatively give you a better idea of whether the culprit is vitamin D deprivation. Healthline lists other symptoms as stress fractures and bone breaks, severe bodily pain (such as the inability to walk up a flight of stairs or sit down without hurting), and extreme fatigue.

If you notice you're feeling extremely sore or tired in any of these ways, it's definitely worth it to go see a doctor, as the only way to get a good look at your vitamin D levels is via a blood test. However, Harvard Health warns most people against getting these blood tests, arguing that "it isn't helpful for most people to know their vitamin D levels," unless their pain is very severe, or if they are falling a lot. Similarly, Harvard Health says that a vitamin D supplement will only be helpful for those who are falling down due to bone and muscle density issues.

According to the ODS, the most common foods with the highest concentration of vitamin D are fatty fish like tuna and salmon, and smaller amounts of the vitamin can also be found in cheese, beef liver, and egg yolks.

All that dairy and meat might sound a bit alarming for vegans who are worried about their vitamin D levels, but if you're a plant-based eater, don't stress it.

Again, Harvard Health explains that vitamin D levels in most people are pretty much self-sustaining, and you shouldn't worry about them too much, unless you're feeling drastic levels of bone aches or fragility.

Another slightly controversial aspect of vitamin D is the question of how much you should be trying to take in on a daily basis. The simple answer to this is that there's no general consensus. According to the Institute of Food and Agricultural Sciences, the current daily estimate of vitamin D that you need is around 600 international units (IUs) a day, and it goes up a bit to 800 IUs per day if you're over 70 years old. FYI, international units are a type of measurement that's standard for vitamins and supplements.

Of course, if you're feeling kind of sore, you could always clear your plans for the next Saturday afternoon, grab a picnic blanket, and lie out under the sun for a few hours. If anyone asks, you can simply explain that you're regenerating your vitamin D levels, and that you'll talk to them later.