You’ve just woken up from a nap on your lounge chair. Somehow, even with the sun shining overhead, you still managed to doze off. You then reach out toward the table nearby and grab your frozen cocktail. Taking a sip, you think to yourself, “Life is good.” But all of that sun exposure may actually be harmful than you think.
Vitamin D is unlike most of the other nutrients that your body needs. We’ll give you a hint as to why – some people refer to it as the “sunshine vitamin.” And that’s because, as your skin is exposed to sunlight, it begins to produce a hormone using your cholesterol supply called vitamin D.
Still, it’s tough to get all of the vitamin D your body needs – even if you’re basking in the sun! If you plan to get your supply from the foods you eat, well, that’s a tough task, too. Only a few foods apparently contain a sizable amount of it. And that’s why nearly 42 percent of all Americans are deficient in vitamin D, according to Healthline.
That’s not to say you can’t find vitamin D in what you eat, though. Healthline notes that there are two food-based sources of it: vitamins D3 and D2. You’ll find the former in animal products such as egg yolks or fish – especially fattier varieties. Meanwhile, the latter appears in some plants, mushrooms and even yeast.
Experts have found that the animal-based sources of vitamin D are much more effective at raising the amount of it in the blood. If you can’t or don’t want to eat high-in-D3 foods – such as salmon, herring and eggs – you still have the opportunity to get the vitamin from what you eat. You just need to make sure that it’s a fortified product.
This is great news for those who follow plant-based diets or just don’t like the natural sources of vitamin D. Some food products come fortified with it to help you get your daily dose. Keep your eyes peeled for cow and soy milk that have added vitamin D, as well as orange juice, cereal and oatmeal.
Most of these fortified sources contain a noteworthy amount of vitamin D – although none can provide 100 percent of your recommended daily intake in a single serving. According to Healthline, fortified cow’s milk can have up to 22 percent of the amount you need. Enhanced cereals offer you up to 17 percent, meanwhile, and orange juice with added vitamin D contains about 12 percent.
How much vitamin D should you be getting, then? Well, experts say that depends on a slew of factors – such as age and race. Your geographical location can reduce or increase that number, too. Those who live in sunnier locales and wear clothing that exposes more skin to the sun, for example, will need less than those who get darker, gloomier winters.
Nevertheless, the US Institute of Medicine says that 97.5 percent of the population needs between 10 and 20 micrograms of vitamin D – or 400 to 800 international units (IUs). For reference, this is a measurement used for fat-soluble vitamins. Though without proper sun exposure, this number may have to increase.
Sure, this is a lot of information to take in. But one major piece of the puzzle is missing: why would you bother to take vitamin D in the first place? As it turns out, getting your recommended daily intake will give you a wealth of benefits. Though be warned: there can be a bad side of vitamin D, too.
Getting your daily dose of vitamin D can stand as your first line of defense against a slew of illnesses – from common ones to rarer, more severe afflictions. Clinical dietician Lana Nasrallah told Health in June 2020, “It can support the immune system by fighting off harmful bacteria and viruses.”
But it’s not just immunity against run-of-the-mill colds and viruses that’s on the table. Vitamin D has also shown its power in tackling cancer, too. Michael F. Holick – who leads Boston University School of Medicine’s Vitamin D, Skin and Bone Research Laboratory – spoke about its most impressive protective properties with WebMD.
Holick explained, “Activated vitamin D is one of the most potent inhibitors of cancer cell growth.” Considering millions of people each year receive cancer diagnoses, this is an important detail to know. Other research has shown that vitamin D can help ward off one of the most common types – bowel or colon cancer.
The Journal of the American Medical Association published a study in 2003 that highlighted promising links between vitamin D and colon cancer reduction. More than 3,000 ex-service people participated in the research, which took place at 13 Veterans Affairs medical outposts. And those individuals who ingested over 645 IUs of vitamin D each day along with cereal fiber – 4 grams of it or more – saw their risk of developing precancerous polyps slashed by 40 percent.
Holick also pointed out vitamin D’s effectiveness in reducing high blood pressure – results he and his team had uncovered in a study at Boston University. They put participants through a three-month trial, during which they were exposed to UVA and UVB rays. This boosted their vitamin D levels by 100 percent – a noteworthy finding on its own.
But it was the fact that this process reduced their high blood pressure that proved even more impressive to Holick and his team. And the results weren’t fleeting either. He said, “We’ve followed them now for 9 months, and their hypertension continues to be in remission.” It’s currently unclear how vitamin D has this calming effect. Though experts theorize that it might stall the production of a hormone called renin, which may boost blood pressure.
Simply taking a multivitamin supplement inclusive of vitamin D can provide some passive disease-fighting properties, too. A study published in Neurology in 2004 revealed that women who took at least 400 IUs daily hadn’t just upped their vitamin D levels. No, they’d also warded off a multiple sclerosis diagnosis in the future by 40 percent in comparison to their non-vitamin-taking counterparts.
And then there’s vitamin D’s links to diabetes. Jackie Newgent – a culinary nutritionist who wrote The Clean & Simple Diabetes Cookbook – told Health that studies were still inconclusive. Still, there seemed to be some promising findings. A daily intake of greater-than-800 IUs of vitamin D – alongside more than 1,200 milligram of calcium – could reduce a person’s chances of developing type-two diabetes.
And Dr. Holick – who runs the Boston University School of Medicine’s Vitamin D, Skin, and Bone Research Laboratory – told WebMD that the vitamin “also stimulates your pancreas to make insulin.” Those familiar with diabetes will know that the insulin hormone is at the center of the condition. Namely, those with type-two diabetes either produce too little of it or can’t use it effectively. So, for many, stoking pancreatic production could be a huge benefit of getting their daily dose of vitamin D.
If vitamin D can be such a resource to fight disease, it’s not hard to believe that it can do wonders in our daily lives, too. You may have an inkling as to why you should get your daily dose of the stuff. One of the majorly touted benefits of vitamin D, for instance, is the vital role it plays in building and strengthening bones.
It’s not directly responsible for bone-building – that’s up to calcium – but it does foster the body’s use of the latter mineral. Culinary nutritionist Jackie Newgent explained to Health, “Vitamin D promotes absorption of calcium in your gut, which ultimately allows for normal mineralization of your bones.”
Newgent went on, “You need vitamin D for bone growth – and to prevent bones from becoming brittle.” To this point, we do get a disease-fighting benefit, too. Getting the right amount of this vitamin plus calcium can also ward off osteoporosis, which degrades bone density and quality over time.
And it’s not just bones that could suffer without vitamin D. If you want a strong frame, you need the stuff for more reasons than one. Clinical dietician Nasrallah added, “Lack of vitamin D in the body can increase the risk of having weak muscles, which, in turn, increases the risk of falls.”
Much like osteoporosis, weak muscles tend to appear in older adults. They can cause the elderly to fall and even break bones weakened by a lack of calcium and vitamin D. Nasrallah explained that falling “is a common problem that leads to substantial disability and death in older adults.”
And if vitamin D fortifies the bones, it stands to reason that it can protect your pearly whites, too. This traces back to the fact that it helps the body to absorb calcium. In terms of oral health, though, The Journal of the Tennessee Dental Association claims that this mineral-vitamin combo can reduce your risk of developing gum disease or tooth decay. So, it can help to keep your mouth healthier for longer.
And it turns out that vitamin D can make you grin, too! You know that stepping out on a sunny day makes you feel good, right? Well, in a 2017 article published in Neuropsychology, researchers revealed “a significant relationship between depression and vitamin D deficiency.”
At the time, the researchers did note that they would need to do more studies to figure out causation. Was it vitamin D deficiency causing the depression – or vice-versa? Though they did suggest that “screening for and treating vitamin D deficiency in subjects with depression” would be a quick, budget-friendly way to help them feel better.
At this stage, you may be ready to reap all of the goodness that vitamin D has to offer you, but you’re not quite sure where to start. You might think you should step outside in your swimsuit, lay down and let the sun work its magic. Not so fast: taking in your vitamin D in the wrong way can do more harm than good, according to The Journal of the American Medical Association (JAMA).
Let’s say you wish to incorporate supplements into your routine to make sure you get your daily recommended intake of vitamin D. As per the US Institute of Medicine, that should be somewhere between 400 and 800 IUs – or 10 to 20 milligrams – for 97.5 percent of people. Once you start taking it, though, you may think that you might get even more benefits if you take an extra-large dose of D.
Though Harvard Medical School’s Michael and Lee Bell Professor of Women’s Health Dr. JoAnn E. Manson warned against taking too much vitamin D. She told Harvard Health Publishing in 2017, “More is not necessarily better. In fact, more can be worse.” Plenty of studies backed up her statement, too, as they proved that too much vitamin D could actually reverse its good effects.
In a 2010 study published in JAMA, older women who took extra-large doses of vitamin D were found to be more likely to fall and suffer from fractures. As you’ll recall, the right amount of vitamin D will help your body fortify bones with calcium. And it’ll strengthen muscles, too – paradoxically helping to prevent both of these scenarios.
Yet it’s not just falls and fractures that could be on the cards if you take too much vitamin D. An excess of it can cause a predisposition for kidney stones in women, according to Harvard Medical School. It can also lead to hypercalcemia – a build-up of calcium in the blood – which can cause soft tissue and arterial deposits. And then, there’s the chance of toxicity, too.
Another danger when it comes to vitamin D is if you choose to get yours from the sunlight. To truly reap the benefits of it, the U.K.’s National Health Service (NHS) claims that you have to step out with your forearms, hands or legs uncovered. And you apparently can’t wear sunscreen. Otherwise, you’ll block out the rays you need to produce vitamin D.
But too much exposure to the sun – and even to artificial sources of its rays such as tanning beds – can cause a person to develop skin cancer. So, be cautious of how much time you spend without your skin covered by clothes or sunscreen to avoid permanent damage to your epidermis.
The good news is that it doesn’t really matter where you get your vitamin D from, according to Yale Medicine’s chief of dermatologic surgery David J. Leffell. He told the school’s website in 2018, “There are claims that one needs to get a certain amount of sun exposure every day in order to produce enough vitamin D to be healthy. It’s just not true. The majority of people can get their vitamin D from nutritional supplements and from vitamin D-fortified foods.”
So, you may be inspired by this big list of benefits – and its handful of avoidable negatives – to start making your vitamin D intake a focus of your healthy living routine. You could make things simple and reach for a supplement that promises to fulfill your daily requirement. Yale Medicine notes that you should aim for 600 IU if you’re a healthy adult, and 800 IU if you’re a healthy adult over the age of 70.
Or, you might try and prioritize vitamin D-heavy foods so that you get it from an all-natural source. Again, it doesn’t matter where you get the stuff from, but there are some foods that prove higher in the vitamin than others. Your best bet is to incorporate more fatty fish into your diet. For instance, options such as swordfish will provide 566 IUs in a 3-ounce serving, according to the Cleveland Clinic.
You can also pick up more IUs from other, non-fishy foods. Although the amounts won’t be as significant. The clinic’s website claims that a large egg’s yolk will typically contain about 40 IUs, while a slice of Swiss cheese will up your tally by 6 IUs. Don’t forget that fortified options have lots of vitamin D, too – a tablespoon of fortified margarine, for example, will contain about 60 IUs.
Like we said, it’s tougher to get things right when it comes to sun exposure, since everyone’s skin type and tone is different. A study funded by Cancer Research UK found that most Caucasians need about 9 minutes of sunlight around lunchtime to soak up the most effective vitamin-D-creating rays. Those with darker skin might need closer to 25 minutes to get the same amount. Again, be cautious and when in doubt, stick to supplements and food-based sources.
In the end, what you’ll get will do your body good. You will top up your supply of vitamin D, which has a wealth of health benefits for people in every stage of life. You’ll strengthen your frame, potentially ward off disease and boost your mood, too. And, if the latter benefit is any indication, you’re going to feel good for doing it!