When the sun’s ultraviolet (UV) rays connect with your skin, it triggers vitamin D synthesis, the process your body uses to create and store vitamin D. How much time you spend in the sun, the color of your skin, and your age all play a role in how much vitamin D is synthesized each time you’re in the sun. Your body also has mechanisms that keep it from producing too much vitamin D.
When it comes to getting sun exposure, most experts recommend spending about five to 30 minutes in the sun several times a week. Ideally, you should be in the sun sometime between 10:30 a.m. and 4 p.m.
But keep in mind that this timeframe is also when the sun’s rays are the most powerful. If you are going to be in the sun without sunscreen, you need to be cautious not to burn your skin.
While sun exposure can help you build up your vitamin D stores, it also comes with some risks. Sun exposure can cause skin cancer, wrinkles, premature aging, and other types of skin damage. It may also suppress your immune system and your skin’s natural defenses. Some expert organizations, like the American Academy of Dermatology Association, say there is no safe amount of sun exposure.
Not getting enough sunlight can also pose significant risks. Research suggests that a lack of sun exposure may be linked to 340,000 deaths in the United States each year. People who avoid the sun have an increased risk of death similar to people who smoke.
To determine whether you need to spend more time in the sun and how much time you need a week, talk to a healthcare provider familiar with your medical history, including the medications you take and any pre-existing conditions you have.
When determining how much sun you need for vitamin D, there are several factors you should consider. These include your age, skin tone, geographical location, and overall vitamin D levels.
Skin Tone
People with lighter skin tones have a higher risk of sunburn, so they may need to limit their time in the sun. People with darker skin tones may need to spend more time in the sun because their bodies do not make vitamin D as easily.
In one study, researchers found that 90% of white people need about 30 minutes of summer sun three times per week to get enough vitamin D, while people with darker skin would need more exposure.
Time of Day and Year
If you primarily get sun exposure before 10:30 a.m. or after 4 p.m., you may need to spend more time outside to get enough vitamin D through sunshine. This is because the sun is not as strong earlier and later in the day.
The summer sun is typically the strongest. In other seasons, you may need to spend more time outside during the day to get adequate sun exposure. This may partly depend on your location.
Geographical Location
Where you live plays a role in your sun exposure. People in the northern part of the U.S. are more prone to vitamin D deficiency than people in southern states like Florida or Texas. This is because the sun’s rays are not as strong or there may not be as much sun in some areas.
Your geographical location may make getting vitamin D from the sun more challenging than in other areas of the country. Consider the time of year and your location when determining whether spending time in the sun is worth it.
Age
As you age, it becomes harder for your body to make vitamin D. If you are over 70, you may need more of the nutrient than younger people. Your body may be less efficient at absorbing vitamin D, as your liver and kidneys become less effective at converting vitamin D into its usable form.
As people age, they often spend less time in the sun and need to be more intentional about getting sufficient sun exposure.
Many healthcare providers recommend that older adults take vitamin D supplements to meet their intake needs. Vitamin D deficiency in older people can lead to reduced bone density, muscle weakness, and an increased risk of falls.
Vitamin D Status
To determine your vitamin D levels, a healthcare provider can order blood work. This test will show if you meet the recommended 20 nanograms per milliliter (ng/mL) or above for overall health. Some healthcare providers may recommend keeping your vitamin D status at 25-30 ng/mL, but not exceeding 50 ng/mL.
If you are deficient in vitamin D, you will need to boost your vitamin D intake through supplements, food, and possibly the sun. Low vitamin D levels can weaken your bones and immune system and impact your overall health.
Dermatologists recommend wearing a broad-spectrum sunscreen with an SPF of 30 or higher every day. Many people worry that wearing sunscreen on a daily basis may reduce their vitamin D production. However, research on this is still ongoing.
One study notes that while sunscreen can decrease your body’s ability to synthesize vitamin D, 15.6% of UV radiation still penetrates the skin and is absorbed. This means your body may still be making vitamin D even when you are wearing sunscreen. The researchers noted that wearing sunscreen can protect your skin from damage while still allowing some vitamin D production.
Sunscreen is not the only contributing factor to vitamin D deficiency. Age, diet, and certain health conditions can all play a part. Most skin health experts recommend protecting your skin with sunscreen and supplementing with vitamin D when appropriate.
Relying on the sun for your vitamin D levels can sometimes be challenging and, in some cases, dangerous for your skin. For this reason, it’s important to know where else you can get this nutrient.
There are very few food sources that have vitamin D naturally, but you can find vitamin D in fortified foods like milk, cereals, orange juice, and some plant-based milks. You will also find vitamin D in foods like salmon, tuna, mackerel, beef liver, egg yolks, fish oils, and some mushrooms.
Many people meet their vitamin D needs with supplements, especially in the winter months when the sun is not as strong. Supplements can make it easier to meet the recommended daily vitamin D intake. People under 70 years old need 600 international units (IU) of vitamin D per day, while people over 70 should get 800 IU.
Before taking a vitamin D supplement, talk to a healthcare provider for guidance. Vitamin D is a fat-soluble vitamin, meaning that your body stores it. If you take too much, it could become toxic to your body and elevate your calcium levels. This could lead to kidney and heart issues as well as complications with your bones.
Spending time in the sun can help your body produce vitamin D. Experts generally recommend spending five to 30 minutes in the sun daily between 10:30 a.m. and 4 p.m. to boost vitamin D production.
Whether or not you can get enough vitamin D while wearing sunscreen is still being studied. Most dermatologists recommend wearing sunscreen to protect your skin, while other health experts may recommend small amounts of sun exposure without sunscreen to boost vitamin D.
Talk to a healthcare provider familiar with your vitamin D status, medical history, and medication use to determine what type of sun exposure is best for you. Other options for getting vitamin D include taking supplements and eating fortified foods, oily fish, egg yolks, and beef liver.
