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Column originally published Aug 26, 2014
Column last revised/updated on Jul 26, 2018

UV Radiation, Sunscreen And Vitamin D

Question: My husband came from Africa and has very dark skin. We have a six-month-old son; his skin is not as dark as his father. I have very fair skin and burn easily when I stay under the sun for any length of time. I have been using sunscreen all my life. I wonder what we should do with our son, whether he needs sunscreen like me or not. As I use sunscreen all the time, am I getting enough vitamin D or should I take a supplement instead?


You have several very timely questions. Before answering them, I need to explain a little about UV radiation and different skin types.

There are three types of ultraviolet rays from the sun: UVA, UVB, and UVC. The last one, UVC, is completely absorbed when it passes through the atmosphere, so we don’t have to worry about it here on earth. UVA is mostly responsible for causing skin damage and skin aging, as well as tanning of the skin. UVB is the main cause of sunburn: the skin becomes red, hot, painful, sometimes blisters, and later peeling. Both UVA and UVB can cause damage to the DNA of skin cells and lead to skin cancer.

The risk of sunburn depends on the amount of dark pigment called melanin in the skin. Dermatologists have classified us into 6 skin types, based on skin colour and tendency for sunburn. Type 1 are those who have pale white skin that always burn and never tan; type 2 have white skin that burn easily and tan minimally. Type 3 have white skin that burn minimally and tan easily; type 4 have light brown or olive skin that burn minimally and tan easily. Type 5 are those with brown skin that rarely burn and tan easily and darkly; type 6 have dark brown or black skin that rarely burn and always tan darkly.

It is important to note that even those with very dark skin like your husband can still burn when exposed to the sun for long enough period of time. It is not easy to see the sunburn, but it will still be painful and can blister and peel. If he is in the sun for a long time, he should apply sunscreen also.

Your son has lighter skin than his father, which means that he can tan, but can get sunburn easier than his father. You should put sunscreen on him when he is out in the sun for longer period of time.

Most of the sunscreens sold in Canada nowadays have broad spectrum protection for both UVA and UVB. There is a sun protection factor, or SPF, which indicates how effective it is to prevent sunburn. The minimal SPF recommended is 15, and SPF 30 is enough for almost everyone. It is generally not necessary to spend much more money on sunscreens with higher SPF.

The most important thing to know about sunscreen is how to use it properly. If you are planning to be in the sun for a good period of time, you should apply the sunscreen about 15-30 min before going out there. You need to apply it over all exposed area, and make sure that you use enough of sunscreen; most people tend to use too little and miss parts of the exposed skin. Although some sunscreens claim to be waterproof and sweat-proof, it is advisable to reapply every two hours to ensure best protection. Every time you get sunburn, you increase your chance of developing skin cancer down the road.

In addition to sunscreen, it is important to wear a wide-brim hat that shades the eyes as well as the ears. Wearing long-sleeve shirts and pants can protect the arms and legs. The sun’s rays are strongest between 10 am and 4 pm; one should avoid staying under the sun during that period of time. It is also very important to wear sunglasses, even for young children, to reduce UV damage to the eyes.

Many weather applications on smartphones include UV index in the app.  This index tells us how likely we can get sunburn depending on the skin type that I have mentioned earlier.

Finally, you have an interesting question about Vitamin D. It is also known as sun vitamin because it is produced in the skin following sun exposure. Because of extensive use of sunscreen, there is some concern whether we are getting enough Vitamin D or not. It was said that if one gets sun exposure on the face, arms, hands, or back, for 10-15 min at least twice a week without sunscreen, there will be enough vitamin D produced for the person.

My advice for many parents is this: if you are out in the sun for a short period of time, don’t use sunscreen, but wear long-sleeve clothing if possible and wear a wide-brim hat and sunglasses. This will allow your body to absorb the necessary UV radiation and produce Vitamin D. Those who have dark skin will need longer exposure to the sun, because the pigment melanin blocks some of the UV rays. If in doubt, take Vitamin D supplement instead of risking sunburn and skin cancer.