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 light skin synthesize vitamin D faster than people with dark skin. The reason is that people with light skin have less melanin.

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

Morning sun exposure helps the skin create vitamins necessary for the body.

PHOTO: AI

According to research published in The Journal of Clinical Endocrinology & Metabolism , people with fair skin only need 10-15 minutes of sun exposure to their arms, legs, 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.

Elderly people have a 50% reduction in their ability to synthesize vitamin D.

In the elderly, the ability to synthesize vitamin D is reduced by up to 50% compared to young people, due to thinner skin and less 7-dehydrocholesterol. Therefore, they need to expose themselves to the sun for longer or combine vitamin D supplements through food. It is important to note that sun exposure after 9-10 am when strong UVB rays can damage skin cell DNA, increasing the risk of skin cancer.

Another key factor is the amount of skin exposed to sunlight. Experts say that about 25-35% of the body's skin should be exposed, such as the arms, legs, face and neck, for 10-15 minutes. This can help the body synthesize about 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 is still within the allowable range of 4,000 IU per day.

If only small areas like the face and hands are exposed to the sun, the amount of vitamin D synthesized is greatly reduced, only 10-20% of the maximum level. Therefore, those who wear protective clothing or live in areas with little 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