Doctors have recently found that the majority of those who live in cool climates are vitamin d deficient. all this is in spite of the fact that some fish contain vitamin d and milk, cheese and ice cream are fortified with vitamin d. vitamin d supplementation is therefore a very good idea for excellent health. vitamin d deficiency classically causes rickets and osteomalacia (thin bones) and is more common in children who are vitamin d deficient. prolonged breastfeeding is a cause of rickets in some children who don’t get enough vitamin d in their breast milk. excessive use of sunscreens can cause vitamin d deficiency. in adults, vitamin d deficiency can cause bone weakness and boney pain.those who are especially encouraged to supplement with vegan vitamin d include those greater than age 50 that are at increased risk of developing vitamin d deficiency. people with limited sun exposure should also consider supplementation, especially if they are homebound and live in northern latitudes. people with dark skin don’t get enough vitamin d in their system. those with fat malabsorption need to be supplemented with vitamin d and other fat soluble vitamins. those who are obese and have a bmi greater than 30 often are vitamin d deficient and should supplement with vitamin d. vitamin d is used to support those with osteoporosis, those with fragile bones and an increased risk of bone fractures. insufficient vitamin d can contribute to osteoporosis by reducing calcium absorption