Risk factors Research has shown that some people are at a higher risk of developing a vitamin D deficiency than others. Some risk factors to becoming deficient are: Advertisement Skin tone People with darker skin tones are more likely to be at risk of a vitamin D deficiency because they contain more of a pigment called melanin, which reduces the skin's ability to absorb UV radiation from the sun. While this better protects darker-skinned people from sunburns, it also means they don't produce as much vitamin D when exposed to the sun. Advertisement Conversely, light-skin people, especially those with a family history of skin cancer, may actively choose to avoid the sun to protect their skin from damage. Without enough sun exposure, they too are at risk of a vitamin D deficiency.