维生素 A 不只在面霜里：15 种食物的含量账，还有一条过量警告

Anybody who is serious about anti-aging is using retinol in their beauty routine. The ingredient, which is a derivative of vitamin A, is considered the gold-star anti-aging ingredient when it comes to skin health. Vitamin A—whether it’s in the form of retinol or one of the other retinoids, like retinoic acid or retinyl palmitate—has been clinically proven to smooth lines, clear acne, and reverse sun damage because it supports cellular turnover.

But vitamin A doesn’t just come in a tube. There are plenty of foods that are rich in vitamin A, which is almost totally bioavailable and benefits more than just your skin. Eating a diet rich in vitamin A helps to support healthy immune and reproductive systems; when you’re applying it topically, it’s solely focused on dermal cellular turnover.

“Diet plays a significant role in our skin’s health and appearance,” says Manhattan-based board-certified dermatologist Dendy Engelman, MD, FAAD. “There are studies to support that increased vitamin intake helps skin in both the aging space and acne.”

Here’s how you can take advantage of vitamin A in your diet to improve your skin, immune system, and more.

Benefits of Vitamin A

Vitamin A is a fat-soluble vitamin (more on that later) that is key for a healthy body. “The human body does not produce vitamin A, so it must be obtained externally through our diet and skin care,” Dr. Engelman says. “Retinol, like other retinoids, is a derivative of vitamin A. When applied topically to the skin, it is converted to retinoic acid, the active form of vitamin A in the body.”

When it comes to the edible form, vitamin A comes in two forms: retinol, which is found in foods that originate from animals; and carotenoids, which are derived from plant-based foods and converted into vitamin A when digested.

“Appropriate vitamin A intake helps support healthy skin, hair, and nails,” Dr. Engelman adds. “Vitamin A plays a role in regulating sebum production and cell turnover, which are important for maintaining a healthy skin barrier (including the scalp) and supporting the hair growth cycle. Vitamin A is also necessary for the synthesis of keratin, which is a vital structural protein for both hair and nails.”

Daily Requirement of Vitamin A

Daily vitamin A requirements vary depending on age, sex, and health conditions (and if you’re pregnant or breastfeeding). According to the Mayo Clinic, adult males should take 900 micrograms (mcg), and adult women should take 700 mcg. It is important to note that the body does not need large amounts of vitamin A every day, but regular, balanced intake is essential to maintain the right balance and prevent deficiencies.

A Warning About Vitamin A–Rich Foods

“It’s important to note that consuming too much vitamin A can actually be very toxic for the human body, leading to a condition known as hypervitaminosis A,” Dr. Engelman points out. “This can result in a number of unwanted and potentially dangerous side effects—including, ironically, a disrupted and unhealthy skin barrier, and hair loss. Therefore, it is very important to avoid excessive consumption of vitamin A—or any compound!—and speak with your doctor to determine the diet that’s best for you.”

15 Vitamin A–Rich Foods

• 3 ounces of liver (especially beef or chicken), which will meet the daily dose
• 1 cup of fortified dairy products like milk, roughly 185 mcg
• ½ cup cantaloupe, roughly 135 mcg
• 1 large hard-boiled egg, 75 mcg
• 3 ounces of salmon, roughly 60 mcg
• ½ cup raw carrots, roughly 460 mcg
• ½ cup spinach, roughly 570 mcg
• ½ cup raw red peppers, roughly 120 mcg
• 1 sweet potato with skin, which will meet the daily dose
• Chard, roughly 55 mcg
• 5 dried sulfured apricots, roughly 65 mcg
• Peaches, roughly 24 mcg
• 1 whole mango, roughly 115 mcg