While sunlight is one of the best known sources of vitamin D, that doesn’t mean you should skip wearing strong sunscreen.
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Benefits of sunscreen
By now, everyone has heard that they should be wearing sunscreen daily. Why? Beyond preventing signs of premature skin aging, such as fine lines, wrinkles and dark spots, sunscreen can dramatically reduce the risk of skin cancer. In fact, even a sun-protection factor (SPF) as low as 15 can help cut your chances of developing melanoma - the most serious form of skin cancer - by a whopping 50 percent.
Does sunscreen block vitamin D?
Some people worry that using sunscreen will deprive them of getting vitamin D naturally from the sun, because sun exposure is key for the body's vitamin D production. While sunscreen can affect the amount of ultraviolet A (UVA) and ultraviolet B (UVB) light skin absorbs, studies show that there's little evidence vitamin D levels are influenced by the use of sunscreen. And even if sunscreen did affect our ability to get vitamin D, it still would be mitigated by the reality that most people apply insufficient amounts.
“Very few people put on enough sunscreen to block all UVB light, or they use it irregularly, so sunscreen’s effects on vitamin D may not be that critical,” says Macrene Alexiades, MD, a dermatologist in New York City and associate clinical professor at Yale University School of Medicine.
What is a healthy level of vitamin D?
We need this nutrient, because the benefits of vitamin D are critical to a healthy body, inside and out. "Vitamin D regulates many physiological processes in the skin, including skin turnover, barrier maintenance and immunity," says Dr. Alexiades. She notes that vitamin D also helps the body absorb and retain both calcium and phosphorus, key nutrients for making healthy bone. Consequences of low vitamin D, on the other hand, include rickets in children and weak bones in adults.
How much vitamin D your body needs depends on a number of factors, including your age. The National Institutes of Health recommends that adults between 19 and 70 years old get 15 micrograms, or 600 international units (UIs), of vitamin D every day.
However, studies show that vitamin D deficiency is quite common, and people in this age group may need at least 1,500 IUs or 2,000 IUs to maximize vitamin D's health benefits. It's best to consult with your health care professional to determine what may be appropriate for you.
While the sun is a primary agent in helping the body obtain vitamin D, it's not the only one. "You can also get vitamin D from a healthy diet that includes foods naturally rich in vitamin D, such as salmon, tuna, sardines, cod liver oil and egg yolks, or foods and beverages fortified with vitamin D, such as cereals, yogurt, milk and orange juice," says Dr. Alexiades.
Effects of not wearing sunscreen
“The risks of exposure to UV radiation without adequate sun protection far overshadow the risks of vitamin D deficiency from sunscreen use,” says Rachel Westbay, MD, a dermatologist at Marmur Medical and clinical instructor at Mount Sinai Hospital in New York City. “Both UVA and UVB rays are known to induce skin cancer of all forms, including melanoma.”
The less serious and more common forms of skin cancer — basal and squamous cell — still “often require surgical removal that risks leaving a scar, which is frequently on the face and heals with an undesirable cosmetic outcome,” she adds.
There are aesthetic reasons to guard against sun exposure, too. Common signs of sun damage that can build up over the years may include wrinkling, pigmentation changes like sunspots and freckles, broken capillaries and uneven skin texture. "At its most severe, it can give the skin a thickened, leathery appearance," Dr. Westbay says.
It's important to note that the same sunscreen guidelines apply to everyone, regardless of skin tone. According to Dr. Westbay, the greater concentration of melanin (or skin pigment) in darker complexions does offer some protection from UV damage, but "the natural SPF protection from a darker complexion is not enough," she says.
In fact, sun damage can be especially hazardous in patients with deep skin tones because detection can be delayed, she says. That's why the majority of adults should have a full body skin screening done at least once a year.
How to apply sunscreen
Apply sunscreen everyday - at least 30 minutes before sun exposure - and often, reapplying every two hours. If you're swimming or sweating, look for a water-resistant formula like Neutrogena Ultra Sheer Dry-Touch SPF 30 sunscreen lotion, which remains effective for up to 80 minutes in the water. Be sure to reapply once you're back on land for adequate protection; a mist like Sun Bum sunscreen spray (which has SPF 30) makes it quick and easy.
Este contenido es solo para fines informativos y no constituye un asesoramiento médico. Consult with your health care provider before taking any vitamins or supplements and prior to beginning or changing any health care practices.
Estas declaraciones no han sido evaluadas por la Administración de Medicamentos y Alimentos. Estos productos no están hechos para diagnosticar, tratar, curar ni prevenir ninguna enfermedad.