The color of normal skin is mainly determined by two factors, one is the content of pigments in the skin, namely melanin, carotene and the content of oxidized and reduced hemoglobin in the skin blood, and the second is anatomical differences, mainly the thinness of the skin. 11-13 year olds who want to whiten their skin can be conditioned by the following ways: 1, sun protection: when you go out for a long time, you can apply sunscreen, wear sun hat, wear long-sleeved clothing, etc., to avoid prolonged exposure to the sun and reduce the damage to the skin; 2, supplement vitamin C: eat more cucumbers, strawberries, tomatoes, oranges, etc., because they contain a lot of vitamin C, which can inhibit the activity of tyrosinase, thereby reducing melanin generation. At the same time, vitamin C can also inhibit the oxidation reaction and accelerate the reduction of melanin, thus having a certain whitening effect; 3, reduce the consumption of additives: avoid eating food containing additives, because too many additives in food can cause a burden on the internal organs, which may cause melanin deposition and affect whitening; 4, use whitening products: you can properly use some whitening products containing natural plant ingredients with whitening and moisturizing factors. can play a certain role in whitening the skin.