How many minutes of sun exposure is needed to get enough vitamin D?

Sun exposure too late can cause sunburn and increase the risk of skin cancer. Therefore, morning, especially from 7-9 am, is considered the most ideal time to safely synthesize vitamin D.

Many studies show that people with lighter skin synthesize vitamin D faster than people with darker skin. This is because people with lighter skin have less melanin.

Melanin in the skin absorbs UVB rays, helping to protect the skin from damage but also reducing the ability to synthesize vitamin D, according to the health website Healthline (USA).

Morning sun exposure helps the skin produce vitamins essential for the body.

PHOTO: AI

According to a study published in The Journal of Clinical Endocrinology & Metabolism , people with fair skin only need 10-15 minutes of sun exposure on their hands, feet, and face, three times a week, to maintain optimal vitamin D levels. Meanwhile, people with medium to dark skin tones may need 30-45 minutes under the same sun conditions.

In older adults, the ability to synthesize vitamin D decreases by up to 50%.

In older adults, the ability to synthesize vitamin D decreases by up to 50% compared to younger people, due to thinner skin and lower levels of 7-dehydrocholesterol. Therefore, they need longer sun exposure or supplement vitamin D through food. It is important to note that sun exposure after 9-10 am should be avoided when strong UVB rays can damage skin cell DNA, increasing the risk of skin cancer.

Another key factor is the percentage of skin exposed to sunlight. Experts suggest exposing about 25-35% of the body's skin surface, for example, hands, feet, face, and neck, for 10-15 minutes. These conditions can help the body synthesize approximately 1,000-2,000 IU of vitamin D. This amount is equivalent to or even exceeds the recommended daily intake of 600-800 IU for adults. However, it remains within the acceptable range of 4,000 IU per day.

If only small parts of the body, such as the face and hands, are exposed to sunlight, the amount of vitamin D synthesized decreases sharply, to only 10-20% of the maximum level. Therefore, those who wear protective clothing or live in areas with less sunlight should consider supplementing vitamin D through foods such as salmon, eggs, mushrooms, or supplements, according to Healthline .

Source: https://thanhnien.vn/can-phoi-nang-bao-nhieu-phut-de-du-vitamin-d-185251029201004688.htm