Anyone can be deficient in vitamin D, and research suggests that 1 in 6 adults in the UK have low levels of vitamin D in their blood. However, certain groups of people are at higher risk of vitamin D deficiency than others. These groups include: Those who are housebound and/or get little to no sun exposure during the summer Pregnant and breastfeeding women People over the age of 65 years old People who are significantly overweight People with darker skin e.g. those of South Asian, Afro-Caribbean or African origin