Vitamin D deficiency

Vitamin D deficiency
Other names	Hypovitaminosis D
The normal process of Vitamin D absorption
Specialty	Endocrinology
Symptoms	Usually asymptomatic
Complications	Rickets, osteomalacia, other associated disorders
Causes	Lack of vitamin D, inadequate sunlight exposure
Risk factors	Age, people with dark skin, obesity, malabsorption, bariatric surgery, breastfed infants[1]
Diagnostic method	Measuring the concentration of calcifediol in the blood
Prevention	Sufficient sunlight exposure, dietary intake
Treatment	Supplements
Medication	Cholecalciferol, ergocalciferol, calcifediol
Frequency	Severe deficiency (<30 nmol/L): Europe 13%, US 5.9%, Canada 7.4%. Deficiency (<50 nmol/L): Europe 40%, US 24%, Canada 37%[2]

Vitamin D deficiency or hypovitaminosis D is a vitamin D level that is below normal. It most commonly occurs in people when they have inadequate exposure to sunlight, particularly sunlight with adequate ultraviolet B rays (UVB).^[1][2][3] Vitamin D deficiency can also be caused by inadequate nutritional intake of vitamin D; disorders that limit vitamin D absorption; and disorders that impair the conversion of vitamin D to active metabolites, including certain liver, kidney, and hereditary disorders.^[4] Deficiency impairs bone mineralization, leading to bone-softening diseases, such as rickets in children. It can also worsen osteomalacia and osteoporosis in adults, increasing the risk of bone fractures.^[1][4] Muscle weakness is also a common symptom of vitamin D deficiency, further increasing the risk of fall and bone fractures in adults.^[1] Vitamin D deficiency is associated with the development of schizophrenia.^[5]

Vitamin D can be synthesized in the skin under the exposure of UVB from sunlight. Oily fish, such as salmon, herring, and mackerel, are also sources of vitamin D, as are mushrooms. Milk is often fortified with vitamin D; sometimes bread, juices, and other dairy products are fortified with vitamin D.^[1] Many multivitamins contain vitamin D in different amounts.^[1]