Vitamin D Deficiency in Iran: A Multi-center Study among Different Urban Areas

Abstract

Background: Recent studies have reported different prevalence of vitamin D deficiency in different sex and age groups in de­veloping countries. In the present survey, we elucidated the prevalence of vitamin D deficiency in a multi-center study among Iranian population. 
Methods: In a random cluster sample of healthy men and women (ranged 20 to 69 years old), a number of 5232 subjects from five urban metropolitans' cities (Tehran, Tabriz, Mashhad, Shiraz and Booshehr) were recruited in 2001. Fasting blood sam­ple was taken from participants and sent to the laboratory for measurement of 25-hydroxy vitamin D level. Meta-analy­sis was performed using fixed effect method for estimation of vitamin D deficiency prevalence in a national level.      
Results: Moderate to severe vitamin D deficiency was estimated in urban areas (except for Booshehr because of its heterogene­ity) equal to 47.2, 45.7 and 44.2% in age groups of <50, 50-60 and 60≤ years, respectively among men and 54.2, 41.2 and 37.5 percent among women in the same age groups. The highest prevalence of moderate to severe vitamin D defi­ciency in men was observed in Tehran. Mashhad and Booshehr had also the lowest prevalence of moderate to severe vita­min D deficiency among men and women.
Conclusion: Iran is a country with high prevalence of moderate to severe vitamin D deficiency and the prevalence of this defi­ciency is more evident in Tehran, capital of Iran. Therefore, consideration of main predictors for vitamin D deficiency in all age groups especially in Tehran is recommended.