Medically reviewed on July 19, 2022 by Jordan Stachel, M.S., RDN, CPT. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
Vitamin D is an essential nutrient that aids calcium absorption and promotes bone and immune health. It occurs naturally in some foods, and the body produces it when exposed to the sun’s UV rays. While the sun is considered one of the best sources of vitamin D3, roughly 42% of adults in the U.S are vitamin D deficient. This problem is especially prevalent in places that get little sunlight. If you have a vitamin D deficiency, you might wonder: how much vitamin D do you get from the sun, and how much is too much?
The daily recommended dose of vitamin D is 600–800 IU for adults. Many people can produce enough vitamin D by spending roughly 30 minutes in the sun a few times a week, but that isn’t true for everyone. The amount of vitamin D the body produces in the sun varies from person to person and depends on your physical environment.
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The amount of vitamin D the body produces when exposed to the sun depends on multiple factors, from the time of day to your distance from the equator. Some of the most important factors to consider include:
While it might seem counterintuitive, you can still get your daily dose of vitamin D without being in direct sunlight. When you sit in the shade, your skin is exposed to scattered UVB rays. These rays aren’t as strong as they would be in direct sunlight, but they still allow the body to produce some vitamin D over time. Sitting in the shade is a good option if you need to spend extended periods outside or have a skin condition that makes you more vulnerable to sun damage.
The farther you get from the equator, the less UVB light that reaches the earth’s surface. This means that people living farther from the equator need to spend more time in the sun to produce an adequate amount of vitamin D. In fact, some people may not be able to produce vitamin D at all during the winter if they live far enough away from the equator.
The sun’s rays vary in intensity throughout the day. In most places, UV rays are strongest between 10 a.m. and 4 p.m., when the sun is at its highest. If you go outside during that window, the body will produce more vitamin D in less time than if you went out in the morning or late afternoon.
Melanin is a substance in the skin that absorbs UVB light to prevent damage. The more melanin you have, the more UVB light is absorbed instead of converted into vitamin D. This means that people with darker skin generally need to spend more time in the sun than people with less melanin to get the same amount of vitamin D.
As a person ages, their body becomes unable to synthesize vitamin D as efficiently. Combined with the tendency for elderly adults to spend less time outdoors, this puts people ages 70 and older at a higher risk of developing a vitamin D deficiency. Healthcare providers often recommend vitamin D supplements for older adults to help combat this.
Vitamin D is fat-soluble, meaning that it can become sequestered in fat cells after being ingested or produced by the body. Because fat cells store vitamin D, people with excess body fat are more likely to have a vitamin D deficiency.
While sunlight is important for vitamin D production, UVB rays can damage the skin over time. Overexposure to sunlight can cause sunburns and increase the risk of developing skin cancer, so it’s important to take precautions to protect your skin when spending time in the sun.
The chance of sun damage increases the longer you stay outside. People with less melanin in their skin can develop a sunburn in as little as 15 minutes in direct sunlight. The risk is even higher for people who are sensitive to sunlight or have conditions like albinism that cause the body to produce little or no melanin.
To reduce the risk of damage, limit the time you spend in the sun or break up sun exposure into short intervals. For some people, spending 15–30 minutes in the sun around midday 3–4 times a week is enough to maintain healthy levels of vitamin D. However, people with more melanin may need to add a little extra time. If you aren’t sure how much time you need, start with shorter periods and gauge your skin’s sensitivity to the sun. You can also ask your healthcare provider for advice.
If you’re going to spend more than 15 minutes in direct sunlight, apply sunscreen to exposed areas 30 minutes before you go outside. The Skin Cancer Foundation recommends using a water-resistant, broad-spectrum sunscreen with an SPF of 30 or higher to protect you from UVB and UVA rays. You should also reapply every two hours and immediately after getting wet or sweating.
While sunscreen reduces the amount of UV rays hitting the skin, it doesn’t stop the body from producing vitamin D. In fact, most people don’t put on enough sunscreen or use it consistently enough to impair vitamin D production at all. Even if you do cover all exposed skin with sunscreen, 2-3% of UV rays will still get through.
When spending time outdoors, many people leave their face and eyes uncovered, leaving them vulnerable to sun damage and photoaging. Sun exposure can damage the eyes over time and lead to cataracts, eye cancers, and eye growths. To protect your face and eyes from the sun, try wearing hats or UV-blocking sunglasses. You can also buy facial sunscreen designed to protect against sun damage without clogging pores or irritating sensitive skin.
Many people don’t get enough vitamin D from the sun alone, especially if they spend most of their time indoors or live far from the equator. Too much sun exposure can also lead to skin damage and cancer, so many healthcare providers recommend relying on other sources of vitamin D.
Adding healthy foods high in vitamin D to one’s diet can be a great way to help prevent a deficiency. Vitamin D3 occurs naturally in some foods, while others are fortified with vitamin D2 during production. If you live in a place that gets little sunlight or have sensitive skin, consider adding the following foods to your diet:
Vitamin D supplements are a good option for people who don’t get enough vitamin D from other sources or live in areas with little sunlight. You can find vitamin D supplements at most pharmacies and grocery stores, and they generally don’t require a prescription. However, you should check the vitamin D content on the label before purchasing. If it is higher than the daily recommended dose, it could lead to other health issues. Before taking new vitamins or supplements, talk to your healthcare provider to ensure that you aren’t taking too much or too little.
If you take steps to protect your skin and don’t overdo it, spending time in the sun is a great way to get some extra vitamin D. If you have a deficiency or need alternatives to sunlight, try adding vitamin D-fortified foods to your diet or talk to your healthcare provider about vitamin D supplements. You can also take an at-home vitamin D test to help ensure that you’re maintaining a healthy level of vitamin D.