Sun exposure and Vitamin D in rural India: A cross-sectional study

Indian J Public Health. 2018 Jul-Sep;62(3):175-181. doi: 10.4103/ijph.IJPH_258_18.

Abstract

Background: Vitamin D deficiency/Vitamin D Insufficiency (VDI) is now recognized as a pandemic. Cutaneous exposure to ultraviolet-B causes photolysis of epidermal 7-dehydrocholesterol, converting it to pre-Vitamin D3 (precholecalciferol), which then undergoes isomerization to form the stable hormone Vitamin D3.

Objectives: The objectives of the study is to determine the status of Vitamin D level among the adults residing in a rural area of West Bengal and to find out the optimal cutoff of the sun exposure for Vitamin D sufficiency.

Methods: This study was a rural community based cross-sectional study. It was done from May 2016 to April 2017 among 197 adults residing in a rural block of West Bengal. Data were collected by interviewing the respondents with the help of a structured pre-tested pre-designed schedule. After interviewing, every individual was examined for height and weight and blood was collected for serum Vitamin 25-(OH) D. Receiver Operating Characteristic (ROC) curves were utilized to find out optimum cut-off for sun exposure using Youden's index. Binary logistic regression was performed to find out the associates of high sun exposure. All analysis was done using R.

Results: Overall VDI was found in 133 (67.5%). Among them, 102 (51.8%) were female. On ROC curve for veritable sun exposure for Vitamin D sufficiency, area under curve was 0.7841 which signifies veritable sun exposure as a good screening tool.

Conclusion: Proper information, education, and communication material regarding various aspects of sun exposure and Vitamin D should be prepared with due consultation of field experts and disseminated to increase awareness among the community.

Keywords: Receiver operating characteristic curves; Vitamin 25-(OH)D; sun exposure.

MeSH terms

  • Adult
  • Body Weights and Measures
  • Calcifediol / blood*
  • Cross-Sectional Studies
  • Exercise
  • Female
  • Health Knowledge, Attitudes, Practice
  • Humans
  • India / epidemiology
  • Male
  • Middle Aged
  • Pain / epidemiology
  • ROC Curve
  • Rural Population
  • Socioeconomic Factors
  • Sunlight*
  • Vitamin D Deficiency / epidemiology*

Substances

  • Calcifediol