OBJECTIVES: Vitamin D deficiency is common at all ages, and low levels of vitamin D have been associated with high incidence of type 1 diabetes. Similar results are not consistent for type 2 diabetes. The aim of the present study was to estimate vitamin D status in newly detected youth-onset diabetes in north India. SUBJECTS AND METHODS: This was a prospective case control study at a tertiary care hospital in north India. Seventy two newly detected youth-onset diabetes subjects (age < 25 years), and 41 age- and gender-matched healthy controls were studied. In addition to basic information and management regarding their diabetes, metabolic parameters and serum 25(OH)D were measured in both the groups. RESULTS: Vitamin D deficiency was seen in 91.1% of the subjects with diabetes, and 58.5% of the healthy controls. Mean ±SD 25(OH)D was significantly low, 7.88 ± 1.20 ng/mL in subjects with diabetes against 16.64 ± 7.83 ng/mL in controls. Sixty percent of cases had severe Vitamin D deficiency compared with 8.3% in controls. Levels of vitamin D did not correlate with clinical parameters, such as gender, body mass index; or with biochemical parameters, such as serum calcium, phosphorus, alkaline phosphatase, fasting plasma glucose, and HbA1C. CONCLUSION: Vitamin D deficiency is common in people with youth-onset diabetes.