Vitamin D deficiency is more common in South Asia and Southeast Asia than is appreciated. Most studies defined 25-hydroxyvitamin D levels [25(OH)D] levels of less than 50 nmol/L (20 ng/mL) as vitamin D deficiency. With this cut-off level, the prevalence of vitamin D deficiency was about 70% or higher in South Asia and varied from 6-70% in Southeast Asia. The determinants for the variation of vitamin D status are skin pigmentation, aging, the sun protection behaviors such as application of a sunscreen, religious, lifestyle and nutritional differences. Advanced age is a known risk factor for vitamin D deficiency. Interestingly, elderly in countries such as Korea and Thailand, had higher 25(OH)D levels when compared with young people. This widespread vitamin D deficiency problem especially in the young generation is an urgent health issue that needs to be remedied.
Keywords: 25-hydroxyvitamin D; Southeast Asia; sun exposure; vitamin D deficiency; vitamin D3.