What Is Vitamin D
Vitamin D is a fat-soluble vitamin that acts as a steroid hormone in the body.
There are two types of vitamin D in the diet:
Vitamin D2 : is found in some mushrooms.
Vitamin D3 : is found in oily fish, fish liver oil, and egg yolks.
D3 is more potent in these two types and raises blood levels of vitamin D by almost twice as much as D2.
A large amount of vitamin D can also be produced on your skin when exposed to UV rays from the sun. Any excess vitamin D is stored in your body fat for later use.
Every cell in your body can absorb vitamin D. This vitamin is involved in many processes, including bone health, immune function, and cancer prevention.
Suggested: Is It Better to Take Vitamin D Every Day or Once a Week?
Q: Do Some People Naturally Have Lower Vitamin D Levels Than Others
A: People with darker skin pigmentation tend to have lower levels, as do people who use sunscreen, dont spend much time outdoors, or are overweight or obese. This is because vitamin D is fat soluble, so it gets trapped in fatty tissue and cant be used by the body as it should be. Gastrointestinal surgery, like gastric bypass, makes it difficult to absorb vitamin D. And as we age, we dont absorb vitamin D well, and we produce less.
Sign Up for Our Free Newsletter
One of the best things you can do to protect and improve your health is to stay informed. Your Health is a FREE e-newsletter that serves as your smart, simple connection to the world-class expertise of Johns Hopkins.
Other Ways To Get Enough Vitamin D
There are other ways to get vitamin D beyond just taking a supplement. Sunshine is an excellent source of vitamin D, and so are many foods.
Spending 10 to 20 minutes in the sun provides 1,000-10,000 IUs of vitamin D. The amount of time you should spend in the sun and the number of IUs youll get will vary on the season, where you live in the world, and how dark your skin is. No matter where you are, the short time in the sun that you spend daily should be unexposed so that your body can adequately absorb the light.
Try incorporating vitamin D-rich foods into your diet, too. Here are some options:
- Fatty fish are high in vitamin D.
- Some mushrooms, like portobello and maitake, have proper levels of vitamin D, especially if theyre grown using UV light.
- The United States fortifies milk with vitamin D. Still, raw milk is known to have naturally occurring vitamin D as well. It may even have a higher concentration of nutrients.
Also Check: Does Vitamin C Help Acne
Can Vitamin D Prevent Or Help Manage Type 2 Diabetes
Cardiovascular Disease Taking vitamin D supplements does not reduce the risk ofheart attack, stroke, or death from heart disease, according to the findings of a randomized, controlled clinical trial involving more than 25,000 participants that was published in the aforementioned January 2019 in The New England Journal of Medicine.
Cancer In the same study, researchers found that vitamin D supplementation was not found to reduce the risk of cancer in participants overall. However, those who had developed cancer and were taking vitamin D were less likely to die early than those who took a placebo. Researchers also found a possible reduction in cancer risk for African Americans, and they called for further study to confirm those results.
Rheumatoid arthritis A small observational study of 44 people with RA and 25 controls found that vitamin D deficiency appeared to be more prevalent among people with RA, suggesting these people may benefit from taking a supplement. But a separate small randomized, controlled trial found that while a vitamin D supplement helped people with RA build stronger bones than the control group, the supplements didnt result in other expected health improvements.
What Does Vitamin D Do
Probably one of the most talked-about vitamin in Canada is vitamin D, and for good reason!
Vitamin D is known as a vitamin but it is actually a hormone that is manufactured in our skin when we come in direct contact with ultraviolet rays from sun exposure.
As you can imagine, here in Canada we don’t always have so much of that which is why the risk for vitamin D deficiency is typically higher in the Northern Hemisphere.
According to Health Canada, a minimum of 40% of Canadians may not meet the vitamin D requirements during the wintertime .
So why is vitamin D important? The benefits of vitamin D in the body are vast as it plays an influential role in many health outcomes. Vitamin D plays a significant role in overall health but particularly in immune and bone health. It is needed for the absorption of calcium and bone mineralization as it enhances the absorption of this mineral in the intestines .
Too little levels of vitamin D can result in low calcium levels in the blood, which can decrease bone density and increase the risk of brittle bones and bone diseases. In combination with calcium, having adequate vitamin D levels is essential for strong and healthy bones.
You May Like: How Long Does Iv Vitamin Therapy Last
Depression And Vitamin D Deficiency
For most people, low vitamin D levels tend to be more of a problem. Deficiency can have a number of health effects, including poor bone health, but it can also impact brain development and functioning. Low levels of vitamin D have been associated with mental health conditions including seasonal affective disorder, depression, and schizophrenia.
However, that does not mean that boosting vitamin D can always cure depression. One randomized controlled trial found insufficient evidence to support the use of vitamin D supplementation as a treatment for depression.
If you are experiencing symptoms of depression, whether or not it’s seasonal, talk to your doctor before you try to self-medicate with a supplement like vitamin D. Your doctor can assess your health and determine if vitamin D might help or if some other treatment would be more appropriate.
Symptoms Of Too Much Vitamin D
Some signs that you might be getting an excessive amount of vitamin D include:
- Appetite loss
If you are experiencing these symptoms, talk to your doctor. Be sure to tell them which supplements, medications, and substances you are taking, including the dosages of each. If your doctor suspects that your symptoms might be linked to too much vitamin D, they may administer lab tests to check your blood serum levels.
Vitamin D toxicity can result in other consequences, including kidney and bone problems. Your doctor may also look for signs of the following problems that can be caused by excess vitamin D.
Recommended Reading: What Vitamins Are Good For Dark Spots On Face
How Much Vitamin D Do You Need
Despite widespread assertions in the popular and scientific press that many Americans have a vitamin D deficiency, the term “deficiency” isn’t strictly accurate. The official definition of a vitamin deficiency means that specific health problems stem solely from the lack of a specific nutrient. An actual vitamin D deficiency results in bone disease, such as rickets, which is rare in the United States.
On the other hand, lower-than-optimal levels of specific vitamins, including vitamin D, may increase your risk of numerous health problems, even though they are not solely responsible for these problems. “Insufficiency” may be a better term for these lower levels than “vitamin D deficiency”.
So far, the most clearly established benefit of vitamin D is that it helps the body absorb calcium and therefore promotes healthy bones. However, a steady drumbeat of studies beginning in the 1980s started to build a case that low blood levels of D were connected with a variety of chronic health problems, leading to claims by a number of researchers that the RDA for D was way too low. The confusion and controversy surrounding optimal vitamin D intake and blood values prompted the U.S. and Canadian governments to request that the Institute of Medicine review the evidence on vitamin D and calcium and update the DRIs.
To learn more about the vitamins and minerals you need to stay healthy, read , a Special Health Report from Harvard Medical School.
What Should Ones Vitamin D Level Be
This question has been hotly, hotly debated. At this time, it depends on whom you ask.
The Institute of Medicine believes a blood level of 20-40 ng/mL should be adequate. The Endocrine Society, the American Geriatrics Society, and some other expert groups recommend a level of at least 30 ng/mL.
As noted above, the party line which I consider reasonable is that most people dont need their vitamin D level checked. In the absence of certain health problems, a low vitamin D level is unlikely in someone who takes a daily supplement.
Recommended Reading: What Is The Best Vitamin C To Take
Where Does Vitamin D Come From
Our bodies make vitamin D when our skin is exposed to the sun. It’s hard to get enough vitamin D from the sun, though. Most kids and adults spend lots of time indoors at school and work. When outdoors, it’s important to protect skin to prevent skin cancer and skin damage from too much sun exposure.
Very few foods have vitamin D naturally. The foods with the most are fatty fish , liver, eggs and fish oils. Kids don’t eat these foods a lot. That’s why food companies add vitamin D to milk, yogurt, baby formula, juice, cereal, and other foods.
Adding vitamin D to foods is called “fortifying.” It’s helpful, but it still may not be enough.
To get enough vitamin D, children often need to take a multivitamin with vitamin D or a vitamin D supplement. Vitamin D is sometimes labeled as vitamin D3.
You can buy vitamin D pills, gummies, chewables, liquids, and sprays in stores without a prescription. Ask your child’s health care provider for advice on choosing the right one.
How Much Vitamin D Should I Get From The Sun
In addition to wondering how much vitamin D should I take, many people wonder how much vitamin D should I get from the sun.
Theres a reason that vitamin D is referred to as the sunshine vitamin. Sunlight exposure on our bare skin is the single best way to get enough vitamin D. Unfortunately most people today dont spend enough time in the sun, due to factors like working long hours inside, living in cold climates, being afraid of sunburns, etc.
In order to get enough vitamin D naturally from the sun its important to get outside and expose your skin to sunlight, without sunscreen. Aim to spend about 1020 minutes in the sun daily with as much of your bare skin exposed as you can, which will help your body produce vitamin D. You will absorb the most sunlight between about 11 a.m. and 3 p.m.
Melanin is a substance that affects how light or dark your skin color is. The amount of melanin you have in your skin also affects the amount of vitamin D you can produce, so the fairer your skin, the more easily you can make vitamin D. If you have dark skin, you will likely need more time in the sun, roughly 40 to 60 minutes daily, to make enough vitamin D.
Eating vitamin D-rich foods like eggs, raw milk and fish can also helps improve your blood levels of vitamin D.
Recommended Reading: Can You Take Vitamin C With Blood Thinners
What Kind Of Vitamin D Supplement Should I Take
There are two different types of vitamin D. Vitamin D2 mainly comes from plant-based foods like UV grown mushrooms, or fortified foods and dietary supplements. Vitamin D3 comes from animals and supplements. Youll get D3 from fish oil, butter, liver, and egg yolks.
Vitamin D is available in supplemental form as a liquid, tablet, or capsule. Some doctors will even give vitamin D injections. D2 typically requires a prescription to get, and D3 is commonly available for purchase over-the-counter. There is some debate about whether D2 is stronger than D3 seeking medical advice is the best way to make sure you get the right form and dosage that you need.
The best form of vitamin D to take as a supplement is D3 although, D2 is acceptable, says Tod Cooperman, MD, founder of ConsumerLab. D3 is less likely to result in errors on blood tests, and high doses may raise levels better. In terms of formulations, liquids and pills are generally both fine . My preference is liquid drops, as you can easily adjust the dose. Plus, you can put it right on food or in a beverage, which should remind you that vitamin D, which is fat-soluble, should be taken with foods that contain fats to improve absorption.
Does Milk Have Vitamin D
For those with dietary limitations or inadequate sun exposure, taking vitamin D supplements can help them meet that daily requirement. However, taking too much vitamin D, can have toxic effects.
Remember, the recommended daily limit for most people is 4000 IU . Vitamin D 5000 IU supplements are at the high end of the spectrum. Typical doses of vitamin D supplements come in 400 IU, 800 IU, 1000 IU, and 2000 IU.
Read Also: What Does Vitamin D Do For My Body
Q: Should People Consider Vitamin D Supplements
A: If the level of vitamin D in your blood is less than 20 nanograms per milliliter, your doctor may recommend taking a supplement. Many women already take calcium and vitamin D supplements together for bone health because vitamin D can help in calcium absorption, and they work best when taken together. Ask your doctor if supplements are right for you.
Does Being A Man Or A Woman Affect How Much Vitamin D You Need
Yes and no. Body size is more influential than sex when it comes to vitamin D intake recommendations, Foroutan says. On average, men weigh more than women. However, the relative amount of body fat an individual has may be more pertinent, since vitamin D is stored in body fat.
A study published online in November 2014 in PLoS One aimed to analyze the effect that body mass index may have on vitamin D dosing targets. Findings suggested that participants who were obese needed 2 to 3 times more vitamin D than their normal-weight counterparts.
But men and women are at different risks for various chronic conditions, which means adjusting your vitamin D target may be helpful for managing symptoms or delaying disease progression.
For example, women may be more likely than men to develop both thyroid disease, per the Department of Health and Human Services Office on Womens Health, and osteoporosis, and a vitamin D deficiency is associated with both, other research suggests. If you live with a chronic disease that is associated with your sex, your doctor may factor in vitamin D as part of your personal management plan.
Also Check: What’s A Good Prenatal Vitamin To Take
Vitamin D: The Healthy Aging Dose
Confused by all the back and forth in the media about vitamin D?
Dont be. Theres actually a pretty easy and straightforward approach that most older adults can take.
In this post, Ill explain what I recommend to most of my older patients, and why.
Ill also address the following frequently asked questions:
- Which type of Vitamin D should I take?
- Do I need to have my vitamin D blood level checked?
- What should ones vitamin D level be?
- Will vitamin D really prevent falls or fractures?
- Will vitamin D prevent dementia, cancer, and/or premature death?
- I am outside a lot. Do I need a vitamin D supplement?
- I heard that a higher level of vitamin D is better for you. How much is too much?
By the way, Im updating this post in part because I was disappointed by the recent NY Times article Why Are So Many People Popping Vitamin D?
Among other things, this article should have had a different headline. The key problem the article describes is that there are too many people being tested for vitamin D. The article does not make the case that too many people are taking vitamin D supplements.
In fact, vitamin D supplementation remains recommended by experts. And as Ill explain below, there are good reasons to believe that vitamin D supplementation is especially useful for older adults.
Now, I do agree with the article in that many people seem to have unrealistic expectations of what vitamin D can do for them.
Do You Need A Vitamin D Supplement
Because there are so many factors that can affect your vitamin D level, its important to talk to your doctor if you suspect youre deficient. They can perform a blood test to see if you may benefit from upping your intake of vitamin Drich foods like salmon, fortified milk, and eggs, or taking a vitamin D supplement, according to MedlinePlus. Again, if you live in a place where winters are cool and dark, you may benefit from a supplement.
Talking with your doctor before supplementing is even more important if youre managing a chronic condition. Not only are the benefits of vitamin D supplements unclear for certain health conditions but theres a chance the supplement may do more harm than good if youre taking a medication that interacts poorly with it.
Another thing to keep in mind is that the Food and Drug Administration doesnt regulate supplements like it does over-the-counter medication and prescription medication. Have a conversation with your doctor about their recommended brand and dose to maintain or improve your health.
Additional reporting by Melinda Carstensen and Jamie Ludwig.
Don’t Miss: Are Vitamin C Packets Good For You