Scientists have found that people who live in cool climates -whether omnivore, vegetarian or vegan- are more prone to lower Vitamin D levels due to insufficient sun exposure. All this is in spite of the fact that some fish contain vitamin D and, most milk, cheese, and ice cream are fortified with Vitamin D for those who follow an omnivore or a vegetarian diet. For vegans rules are the same. People who do not get adequate sun exposure or Vitamin D fortified/rich foods should be more careful about Vit D supplementation.* People with limited sun exposure and darker skin may also consider supplementation, especially if they are homebound and live in Northern Latitudes.*