The following groups of people are more prone to have a deficiency in vitamin D than others:
Those who wear full clothes and do not leave the skin to be exposed to sun
Those who overuse sunscreen limit the skin's ability to synthesize Vitamin D
Those who do not spend more time outdoors
Those who have darker skin tones
Those who are old; these people usually stay indoors and have a reduced level of 7-dehydrocholesterol
Those who are obese
Those who have osteoporosis
Those with chronic kidney or liver condition