Effectiveness of the national vitamin D supplementation program: evaluation of children aged 0–3 years in Karabük province

Key Points

• Children's vitamin D levels improved significantly after the supplementation program.
• The program effectively reduced vitamin D deficiency rates in the target age group by up to 50%.
• Observational analysis of children aged 0–3 years in Karabük province highlights significant benefits from vitamin D intake.
• These findings suggest that national supplementation programs may enhance overall child health outcomes.