防曬霜會導(dǎo)致維生素D缺乏嗎?答案是肯定的

防曬霜會導(dǎo)致維生素D缺乏嗎?答案是肯定的

Exposing skin to sunlight is a convenient way to meet our vitamin D needs, which is crucial for bone health. That might make you wonder: Does wearing sunscreen interfere with vitamin D levels and potentially cause vitamin D deficiency?

將皮膚暴露在陽光下是滿足我們對維生素D的需求的一種方便的方式，這對骨骼健康至關(guān)重要。這可能會讓你懷疑:涂防曬霜會干擾維生素D的水平，并可能導(dǎo)致維生素D缺乏嗎?

The answer is yes. But before you toss your SPF 30, dermatologists say the relationship between sunscreen and vitamin D is much more nuanced than that.

答案是肯定的。但皮膚科醫(yī)生說，在扔掉防曬系數(shù)30之前，防曬霜和維生素D的關(guān)系要微妙得多。

According to Dr. Henry, former president of the American Academy of Dermatology, if sunscreen is supplied in a thick layer it "can effectively block sunlight and cause a lack of vitamin D in skin," He said. A thick layer is defined as roughly equivalent to about 1 ounce.

美國皮膚病學(xué)會前主席亨利博士說，如果涂厚厚的一層防曬霜，它“可以有效地阻擋陽光，導(dǎo)致皮膚缺乏維生素D，”他說。厚厚的一層大約相當(dāng)于一盎司。

"However, in the real world ... most people apply less than this amount," Henry added.

“然而，在現(xiàn)實世界中…大多數(shù)人涂的量少于這個量，”亨利補充道。

So, you may not have to worry about vitamin D deficiency if you're not putting enough sunscreen on in the first place.

所以，如果你一開始就沒有涂足夠量的防曬霜，你可能就不用擔(dān)心缺乏維生素D。

"For the vast majority of the public, there should be no concern with vitamin D levels, but for those who practice rigorous protection, namely, wearing photoprotective clothing, hats, staying in the shade when outdoors, and applying sunscreen -- they do have a higher risk," Henry said.

亨利說:“對于絕大多數(shù)公眾來說，不必?fù)?dān)心維生素D的含量，但是對于那些采取嚴(yán)格保護措施的人來說，比如穿防曬服，戴帽子，在戶外時呆在陰涼處，涂防曬霜，他們確實有更高的風(fēng)險。”

Vitamin D deficiency versus skin cancer risk

缺乏維生素D與皮膚癌風(fēng)險的關(guān)系

Vitamin D is synthesized in skin when it's exposed to UVB wavelengths from the sun.

維生素D是當(dāng)皮膚暴露在太陽的紫外線波長下合成的。

So if 15% to 20% of one's body surface is exposed to sunlight, unprotected, for 15 to 20 minutes, two to three times per week, one could achieve adequate vitamin D levels.

因此，如果一個人身體表面的15%到20%暴露在陽光下，不加保護，每周兩到三次，每次15到20分鐘，就可以達(dá)到足夠的維生素D水平。

"When the skin tans, there is DNA damage, and so with repeated low exposure, the DNA damage could accumulate and potentially increase the risk of skin cancer and photoaging," Henry said. Squamous cell and basal cell carcinoma are the most common skin cancers in humans, and are correlated with the degree of one's sun exposure, while melanoma, the deadliest form of skin cancer is often the result of more intermittent, intense sun exposure, Henry explained.

亨利說:“當(dāng)皮膚被曬成古銅色時，就會有DNA損傷，因此，反復(fù)低強度接觸，DNA損傷就會累積，并可能增加皮膚癌和光老化的風(fēng)險。”亨利解釋說，鱗狀細(xì)胞癌和基底細(xì)胞癌是人類最常見的皮膚癌，它們與人暴露在陽光下的程度有關(guān)，而黑色素瘤是皮膚癌中最致命的一種，它通常是間歇性、高強度陽光照射的結(jié)果。

"Patients need to use sun protection to minimize their risk for skin cancer, and yes it does impede the body's ability to make vitamin D. I tell patients if we found out cigarette smoking increased vitamin D levels, we wouldn't tell patients to smoke," said Dr. Patricia Farris, a dermatologist and fellow of the American Academy of Dermatology. "In other words, you can't recommend exposing patients to a known carcinogen (UV light) just to raise their vitamin D levels."

皮膚科醫(yī)生、美國皮膚病學(xué)會研究員帕特里夏·法里斯說，“患者需要使用防曬物，以將患皮膚癌的風(fēng)險降到最低，是的，它確實會阻礙身體合成維生素D的能力。我告訴患者，如果我們發(fā)現(xiàn)吸煙增加了維生素D水平，我們不會告訴患者去吸煙。”“換句話說，你不能建議患者暴露在已知的致癌物(紫外線)下，只是為了提高他們的維生素D水平。”

To reduce the risk of skin cancer and skin aging, dermatologists recommend practicing sensible photoprotection. That means wearing wide-brimmed hats, sunglasses, and sun protective clothing. Photoprotective clothing, which is labeled "UPF," is tightly weaved, and so "the amount of UV radiation that would penetrate is quite low," Henry said.

為了減少皮膚癌和皮膚老化的風(fēng)險，皮膚科醫(yī)生建議進(jìn)行合理的光防護。這意味著要戴寬邊帽子、太陽鏡和防曬服。亨利說，標(biāo)有“UPF”的光防護服編織緊密，因此“能夠穿透的紫外線輻射量非常低，”亨利說。

"To achieve adequate vitamin D levels, it is best to take a multivitamin each day rather than relying on sun exposure. The former is simple and inexpensive, and at the same time prevents the development of skin cancer and skin aging," Henry said.

“為了達(dá)到足夠的維生素D水平，最好每天服用多種維生素片，而不是依賴于曬太陽。”前者既簡單又便宜，同時還能預(yù)防皮膚癌和皮膚老化。”亨利說。

Vitamin D supplements can also help, and are very effective for those who have low vitamin D levels, Farris added.

補充維生素D也有幫助，對維生素D水平低的人非常有效，法里斯補充說。

In addition to vitamin D supplements, the American Academy of Dermatology recommends getting 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.

除了維生素D補充劑，美國皮膚病學(xué)會建議從健康飲食中攝取維生素D，其中包括天然富含維生素D的食物，如三文魚、金槍魚、沙丁魚、鱈魚肝油和蛋黃，或富含維生素D的食物和飲料，如谷類、酸奶、牛奶和橙汁。