How to Safely Get Vitamin D From Sunlight

Receiving sunlight around midday can help you achieve your recommended vitamin D levels more quickly. Still, excessive sun exposure carries risks.

Vitamin D is an unusual nutrient that many people do not obtain in sufficient amounts.

In fact, it’s estimated that of American adults and of the global population are deficient in vitamin D. Additionally, deficiency rates are estimated as follows:

• 50–60% of nursing home residents and hospitalized patients
• 47% of African-American infants
• 56% of Caucasian infants

This nutrient is produced from cholesterol in your skin when it is exposed to sunlight, which is why adequate sun exposure is vital for maintaining healthy vitamin D levels.

However, too much sun also brings health hazards.

This piece outlines safe methods to obtain vitamin D from sunlight.

The sun is the most effective source of vitamin D

There’s a solid reason vitamin D is often termed “the sunshine vitamin.”

When your skin is exposed to sunlight, it converts cholesterol into vitamin D. Ultraviolet B (UVB) rays from the sun strike cholesterol in skin cells, supplying the energy needed for vitamin D synthesis.

Vitamin D performs numerous functions in the body and is crucial for good health.

For instance, it signals cells in your intestines to absorb calcium and phosphorus — minerals essential for maintaining strong, healthy bones.

Conversely, low vitamin D levels have been associated with serious health issues, including:

• Osteoporosis
• Cancer
• Depressive disorders
• Muscle weakness
• Increased mortality

Moreover, only a few foods naturally contain meaningful amounts of vitamin D.

These foods include cod liver oil, swordfish, salmon, canned tuna, beef liver, egg yolks and sardines. However, you would have to consume them nearly every day to meet your needs.

If you do not receive sufficient sunlight, a vitamin D supplement is often advised.

Keep in mind that the sun’s UVB rays cannot pass through glass. Therefore, people working by sunny windows can still be at risk of vitamin D insufficiency.

Expose your skin around midday

Midday, especially in summer, is the optimal time to soak up sunlight.

At noon, the sun is highest in the sky and its UVB rays are most powerful. That means you require less time in the sun to synthesize adequate vitamin D.

Research shows the body is most efficient at producing vitamin D around noon.

For example, in the UK (between 50 and 60 degrees north), 5 to 15 minutes of midday sun exposure between March and October, three times weekly, is sufficient to maintain healthy levels in Caucasian adults.

For much of the US (between 30 and 40 degrees north), recommended exposure ranges from 4 to 15 minutes between February and November.

The commonly suggested daily intake of vitamin D is .

Skin tone can influence vitamin D production

Skin color is determined by a pigment called melanin.

People with darker skin generally have higher melanin levels than those with lighter skin, and their melanin tends to be larger and darker.

Melanin helps shield the skin from damage caused by excessive sunlight. It functions like a natural sunscreen, absorbing UV rays to protect against sunburn and skin cancers.

However, this presents a dilemma: darker-skinned individuals usually need to spend more time in the sun than lighter-skinned people to produce the same amount of vitamin D. This helps explain the greater prevalence of deficiency among those with darker skin.

Consequently, if you have dark skin, you may need somewhat longer sun exposure to obtain your daily vitamin D.

Living far from the equator

People residing in regions farther from the equator produce less vitamin D in their skin.

In these locations, more of the sun’s rays — particularly UVB — are absorbed by the earth’s atmosphere. As a result, individuals who live farther north or south often need more sun exposure to synthesize enough vitamin D.

Furthermore, those who live at greater distances from the equator may not produce any vitamin D from sunlight for as long as six months of the year during winter.

For instance, residents of Boston, USA and Edmonton, Canada struggle to generate vitamin D from sunlight between November and February.

People in Norway cannot make vitamin D from sunlight .

During those months, it’s important to obtain vitamin D through diet and supplements instead.

Expose more skin to boost vitamin D production

Because vitamin D is synthesized from cholesterol in the skin, exposing a larger skin area to sunlight increases production.

Some researchers advise exposing roughly one-third of your skin to the sun.

The British Skin Foundation suggests daily sun exposure of 10–15 minutes for lighter skin and 25–40 minutes for darker skin.

Just be sure to avoid burning if you remain in the sun for extended periods.

It’s also fine to wear a hat and sunglasses to protect your face and eyes while exposing other parts of your body. Since the head represents a small percentage of total body area, it contributes only a small portion to vitamin D production.

Does sunscreen interfere with vitamin D?

People apply sunscreen to guard against sunburn and reduce skin cancer risk.

Sunscreens contain ingredients that reflect, absorb or scatter sunlight, lessening the skin’s exposure to harmful UV radiation.

Some research found that because UVB rays are necessary for vitamin D production, sunscreen could potentially reduce the skin’s ability to make it.

However, using sunscreen appears to have only a minor effect on blood vitamin D levels during summer months.

A 2019 review of studies found no clear link between sunscreen use and decreased vitamin D absorption, and even reported instances of increased vitamin D. This could be because people wearing sunscreen stayed in the sun longer, allowing sufficient vitamin D synthesis.

Most of these studies were short term. Whether regular sunscreen use affects long-term vitamin D status remains uncertain.

Risks of excessive sunlight

Although sunlight is excellent for vitamin D production, too much exposure can be harmful.

Below are potential consequences of excessive sun exposure:

• Sunburns: The most frequent harmful outcome of too much sun. Symptoms include redness, swelling, pain or tenderness, and blisters.
• Eye damage: Prolonged UV exposure can harm the retina and raise the risk of eye conditions such as cataracts.
• Accelerated skin aging: Long sun exposure can speed up skin aging, producing more wrinkles, sagging or leathery texture.
• Skin alterations: Freckles, moles and other skin changes may result from excess sun exposure.
• Heat stroke: Also called sunstroke, this occurs when the body’s core temperature becomes dangerously high from excessive heat or sun.
• Skin cancer: Excessive UV exposure is a primary contributor to skin cancers.

If you expect to spend extended time outdoors, take steps to avoid sunburn.

It’s advisable to apply sunscreen after 10–30 minutes of unprotected sun exposure to minimize the dangers of excessive sunlight. The appropriate exposure duration depends on your skin’s sensitivity to the sun.

Experts also recommend reapplying sunscreen every two to three hours while outdoors, especially if you are sweating or swimming.

The takeaway

Regular sun exposure is the most natural method to obtain adequate vitamin D.

To sustain healthy blood levels, aim for approximately 4–15 minutes of midday sun several times per week. People with darker skin may require slightly longer. Your exact exposure should be based on how photosensitive your skin is. Just be careful not to burn.

Factors that influence your capacity to make vitamin D from sunlight include the time of day, skin pigmentation, distance from the equator, the surface area of skin exposed, and whether you use sunscreen.

For example, individuals living farther from the equator generally need more sun because UVB intensity is lower in those regions.

They should also consider vitamin D supplements or vitamin-D-rich foods during winter months when sunlight-derived production is limited.

If you plan to be outside for a while, apply sunscreen after 10–30 minutes of brief, unprotected sun exposure to help prevent sunburn and lower skin cancer risk.