Table 2.

Risk factors for vitamin D deficiency in childhood [115].

First Year of Life	1–18 Years
Non-Caucasian ethnicity with dark skin pigmentation
Inadequate diets (i.e., vegan diet)
Chronic kidney disease
Hepatic failure and/or cholestasis
Malabsorption syndromes (i.e., cystic fibrosis, inflammatory bowel diseases, celiac disease at diagnosis)
Chronic therapies: anticonvulsants, systemic glucocorticoids, antiretroviral therapy, systemic antifungals (i.e., ketoconazole)
Infants born from mothers with multiple risk factors for vitamin D deficiency, particularly in absence of vitamin D supplementation during pregnancy	Reduced sunlight exposure (due to lifestyle factors, chronic illness or hospitalization, complex disability, institutionalization, covering clothing for religious or cultural reasons) and/or constant use of sunscreens
	International adoption
	Obesity