Does sunscreen block vitamin D? What studies show

Some people skip sunscreen because they worry it will stop their body from making vitamin D. The worry makes sense. The skin makes vitamin D when sunlight hits it, and sunscreen filters sunlight. This guide explains what the research shows about sunscreen and vitamin D, what the American Academy of Dermatology (AAD) and the NHS recommend, and who may need to pay closer attention to their vitamin D levels. It is part of Skinli's guide on how to choose a sunscreen for your face.

How the body gets vitamin D

Vitamin D comes from three places: sunlight, food and supplements. The NHS says, "The body creates vitamin D from direct sunlight on the skin when outdoors." The type of ultraviolet light that lets skin make vitamin D is UVB, the same type that causes most sunburn.

The NHS says vitamin D "helps regulate the amount of calcium and phosphate in the body," nutrients needed to keep bones, teeth and muscles healthy. A lack of it can cause rickets in children and bone pain from a condition called osteomalacia in adults.

The AAD says vitamin D "is critical for bone health," and that there is not enough evidence that it prevents other diseases such as certain cancers or heart disease.

Does sunscreen lower vitamin D?

The AAD's answer is careful: "Using sun protection may decrease your skin's production of vitamin D." The National Cancer Institute (NCI) lists "lower levels of vitamin D made in the skin because of less sun exposure" as one of the small possible harms of sunscreen.

That sounds like a clear yes. The research is less clear, because of how people use sunscreen in real life.

A 2019 study in the British Journal of Dermatology took healthy volunteers from Poland on a one-week sun holiday in Tenerife, at 28 degrees north, where the ultraviolet index was high. Two groups used SPF 15 sunscreen in a measured amount, thick enough to prevent sunburn. A third group used sunscreen as they chose, and a fourth group stayed at home.

The results:

Group	Sunburn	Change in vitamin D level
SPF 15 with high UVA protection, used thickly	Prevented	Rose
SPF 15 with low UVA protection, used thickly	Prevented	Rose
Sunscreen used as each person chose	Present	Rose the most
Stayed at home, no holiday	Not part of the holiday	Fell by 2.5 nmol/L, a change the study did not find significant

The authors concluded that "sunscreens may be used to prevent sunburn yet allow vitamin D synthesis." Synthesis means the body making it.

The same study says that earlier research on this question gave conflicting results, "possibly, in part, because people typically apply sunscreen suboptimally," meaning people often use too little.

So the balanced summary is this. Sunscreen can lower the vitamin D the skin makes in a given amount of sun. In the Tenerife study, people who used it properly still made vitamin D and avoided sunburn.

Why the AAD recommends food instead of sun

The AAD's position is based on skin cancer risk. It says, "Because ultraviolet rays from the sun and tanning beds can cause skin cancer, the American Academy of Dermatology does not recommend getting vitamin D from sun exposure or indoor tanning."

It goes on: "There is not a safe level of UV exposure from the sun or indoor tanning devices that allows for maximum vitamin D synthesis without increasing skin cancer risk."

Instead, the AAD recommends "that healthy adults should obtain an adequate amount of Vitamin D from a diet that includes foods naturally rich in vitamin D and/or foods/beverages fortified with vitamin D." It says this approach "gives you the vitamin D you need without increasing your risk for skin cancer."

Foods with vitamin D

The NHS lists these sources of vitamin D:

• Oily fish, such as salmon, sardines, trout, herring and mackerel
• Red meat
• Liver (the NHS says to avoid liver if you are pregnant)
• Egg yolks
• Fortified foods, such as some fat spreads and breakfast cereals

"Fortified" means vitamin D has been added. The NHS says cows' milk in the UK is generally not fortified, although it is in some other countries, so check the label where you live.

How much vitamin D you need

The NHS gives these daily amounts:

Who	Vitamin D per day (NHS)
Babies up to 1 year	8.5 to 10 micrograms
Children from 1 year and adults, including pregnant and breastfeeding women	10 micrograms (400 international units)

The NHS also sets upper limits for supplements, because too much vitamin D can be harmful. It says adults should not take more than 100 micrograms a day, children aged 1 to 10 no more than 50 micrograms, and babies under 12 months no more than 25 micrograms. The AAD agrees that "getting too much Vitamin D can cause potential harm." Taking too much over a long time can build up calcium in the body and harm the bones, kidneys and heart, according to the NHS.

The NHS adds one reassuring fact: "You cannot overdose on vitamin D through exposure to sunlight." The risk from too much sun is skin damage.

Who may need extra vitamin D

The NHS names groups who may not make enough vitamin D from sunlight. It says adults and children over 4 should consider a daily 10 microgram supplement all year if they:

• Are not often outdoors, for example if they are frail or housebound
• Live in a care home
• Usually wear clothes that cover most of their skin outdoors

The NHS also says people with dark skin, for example from an African, African-Caribbean or south Asian background, may not make enough vitamin D from sunlight and should consider the same supplement all year. The AAD says research shows people with darker skin tones "may be at increased risk for lower levels of vitamin D."

For everyone in the UK, the NHS says to consider a daily 10 microgram supplement in autumn and winter, because between October and early March the sun is not strong enough to make enough vitamin D.

People with dark skin still need sunscreen. The AAD recommends sunscreen for everyone. Our guide on whether Black people need sunscreen explains why.

Babies and young children

Babies and young children need vitamin D too, and the NHS gives them their own advice. It says babies from birth to 1 year should have a daily supplement of 8.5 to 10 micrograms all year, unless they drink more than 500ml of infant formula a day, because formula already has vitamin D added. Children aged 1 to 4 should have a daily 10 microgram supplement all year. The NHS sun safety page says all children under 5 are advised to take vitamin D supplements.

For sun protection, the FDA and the NHS say babies under 6 months should be kept out of direct sunlight. Our guide on when an infant can wear sunscreen covers sun protection at that age. Ask your baby's doctor about the right vitamin D amount.

Why the study result matters for daily life

The Tenerife study used a strong test. The holiday was at 28 degrees north, in bright sun, and the volunteers used sunscreen in a measured, thick layer. Even so, their vitamin D rose. A normal day at school or work often brings less time in strong sun than a beach holiday. For a face sunscreen worn each morning, the practical question is less about sunscreen and more about whether your diet and season give you enough vitamin D. That is a question for food, supplements and your doctor.

What to do

1. Keep using sunscreen. Broad spectrum, SPF 30 or higher, on skin that clothing does not cover. Our guide on how to choose a sunscreen for your face has the checklist.
2. Eat foods with vitamin D most days, from the list above.
3. Consider a supplement if you fall into one of the NHS groups, or during winter.
4. Talk to your doctor if you are worried. The AAD says, "If you are concerned that you are not getting enough vitamin D, you should discuss your options for getting vitamin D with your doctor." A doctor can check your level with a blood test and advise on the right amount.

If you are using an acne treatment that makes skin more sensitive to the sun, sunscreen matters even more. Our starter acne routine shows how it fits into a simple morning, and our guide to sunscreen for acne-prone skin covers which label words to look for.