Bleaching is the practice of using substances, mixtures or physical treatments to lighten Skin colour. This practice reduces the content of melanin. This is the layer that protects the skin from the sun. When someone bleaches their skin, it thins out and starts to peel off.
It is then exposed to infections and bacteria. People who bleach or rather who have bleached their skin cannot even get vitamin D from the sun since the skin is fragile and may end up damaging it the more. So if you have bleached forget about vitamin D which is very important for absorbing Calcium and promoting bone growth.