What is the ruling on using creams or mixtures to lighten areas of the the body that have changed in color, and is it permissible to use vitamin C pills for body radiance?

There is no harm in temporarily changing skin color using creams and cosmetics. However, permanent change, whether through surgery or other means, is not permissible because it falls under altering Allah's creation, as affirmed by Sheikh Ibn Uthaymeen. It is permissible to use vitamin C tablets for body freshness, as this does not constitute altering Allah's creation. The basic principle regarding the use of these vitamins and medications is permissibility, so long as no harm results from them, in accordance with the Hadith: "There should be neither harming nor reciprocating harm."