BACKGROUND: Vitamin D deficiency has been documented as a frequent problem in almost every region of the world even in the tropical countries and its health consequences are enormous. Infancy and adolescence are age groups particularly at risk of developing vitamin D deficiency. However, there are no data on the Vitamin D status of Filipino adolescents.

OBJECTIVES: To determine the serum 25-hydroxyvitamin D levels in Filipino high school students in selected schools in Quezon City

METHODS: A cross-sectional study of Filipino high school students was undertaken. A total of 97 boys and girls aged 11- 18 years old, attending selected private and public secondary schools in Quezon City participated in the study after parents' consent and students' assent were taken. Serum 25(OH)D levels were determined by electrochemiluminescence immunoassay (ECLIA) using Roche HITACHI Cobas e immunoassay analyzer.

RESULTS: The total serum 25-hydroxyvitamin D levels of the students ranged from 19.92 nmol/L to 88.63 nmol/L with a mean of 52.43 nmol/L. Among the 97 high school students, there was a prevalence of hypovitaminosis D (serum 25 (OH)D <50nmol/L) of 41.2% with 20.6% having deficient (

CONCLUSION: Hypovitaminosis D is highly prevalent among Filipino adolescents in secondary school despite abundance of sunlight. Appropriate interventions are needed to address the problem of poor vitamin D status in schoolchildren.