Related Experiment Video
Updated: Jan 31, 2026

Evaluating Therapeutic Interventions in the SHIP-deficient Mouse Model of Crohn Disease-like Ileitis and Fibrosis
Published on: October 14, 2025
Evaluation of vitamin D3 deficiency: A population-based study in northeastern Iran
Seyed-Alireza Esmaeili1,2,3, Saeed Mohammadian2,3, Shabnam Radbakhsh4
1Division of Immunology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Background And Aim:
In recent years, vitamin D deficiency has become a major worldwide problem that can exert harmful effects. The aim of the present study was to evaluate the sex- and age-related prevalence of vitamin D deficiency in people from Mashhad, northeastern Iran.
Methods:
In this cross-sectional study conducted over a period of 1 year (2015-2016), 7504 subjects who referred to Mashhad medical centers were randomly enrolled in the study. The study population was divided into four groups based on sex and age, as following: group 1, 6 to 18 years; group 2, 19 to 35 years; group 3, 36 to 50 years; and group 4, 51 to 65 years. Since vitamin D levels <10, 10 to 20, and 20 to 30 ng/mL are considered as severe, moderate, and mild deficiency, respectively, we used these criteria for categorizing our population.
Results:
Of the total population in our study, 65.26% (4902; 57.81% of men and 72.07% of women) showed some degree of vitamin D deficiency. In addition, we found that vitamin D deficiency was common in all age groups (6-18, 19-35, 36-50, and 51-65 years), and more common in women (58.5%, 80.12%, 63.83%, and 88.44%, respectively) than men (41.66%, 59.86%, 44.97%, and 84.75%, respectively).
Conclusion:
Vitamin D deficiency is a major health problem in all age groups and is more common in women. This information would help to provide a progressive prevention program to maintain health and manage some of the vitamin-related disorders and diseases that especially affect women.
Related Concept Videos
Vitamins
What is Population Genetics?
What are Populations and Communities?
Conservation of Small Populations
Population Growth
Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin...

