Calcium (Ca2+) and vitamin D (VitD) play an important role in child health. Aims. The investigators evaluated the daily intake of Ca2+ and VitD in healthy children; and the efficacy of Ca2+ and VitD supplementation. Daily Ca2 + and VitD intake was evaluated in consecutive healthy children through a validated questionnaire. Subjects with a daily Ca2 + and VitD intake < 70% of dietary reference intakes (DRIs) were invited to participate in prospective randomized trial with 2 groups of nutritional intervention: group 1, dietary counseling aiming to optimize daily Ca2+ and VitD intake plus administration of a commercially available Ca2 + and VitD supplementation product (Colecalcium®, Humana, Milan, Italy); group 2, dietary counseling alone. At the enrollment (T0) and after 4 months (T1) serum VitD levels were assessed.

Inclusion Criteria:

• Ambulatory healthy subjects (male and female, age range 3-17 years) consecutively observed at our Department for routine clinical examination because vaccination program were considered eligible for the study.

Exclusion criteria

• malnutrition (defined as a weight/height ratio <5° centile);
• presence of chronic systemic diseases (celiac disease, inflammatory bowel disease, food allergy, cystic fibrosis, malignancy, immunodeficiency, tuberculosis, genetic-metabolic disease, primitive bone disease, diabetes and endocrine disorder);
• and use of systemic steroids in the previous 3 months.