Indian Journal of Endocrinology and Metabolism

ORIGINAL ARTICLE
Year
: 2018  |  Volume : 22  |  Issue : 2  |  Page : 249--255

Duration of casual sunlight exposure necessary for adequate Vitamin D status in Indian Men


Vivek G Patwardhan1, Zulf M Mughal2, Shashi A Chiplonkar1, Ann R Webb3, Richard Kift3, Vaman V Khadilkar1, Raja Padidela2, Anuradha V Khadilkar1 
1 Growth and Endocrine Unit, Hirabai Cowasji Jehangir Medical Research Institute, Jehangir Hospital, Pune, Maharashtra, India
2 Department of Pediatrics Endocrinology, Royal Manchester Children's Hospital, Manchester, UK
3 School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester, UK

Correspondence Address:
Anuradha V Khadilkar
Hirabai Cowasji Jehangir Medical Research Institute, Jehangir Hospital, 32 Sassoon Road, Pune, Maharashtra
India

Objectives: To investigate the duration of casual sunlight ultraviolet-B (UVB) exposure required to maintain optimal Vitamin D status (25-hydroxyvitamin-D [25(OH)D]) >50 nmol/L in urban Indian men, using polysulfone (PSU) dosimeters and a sunlight exposure questionnaire. Methods: In healthy men (aged 40–60 years) from Pune (18.52° N, 73.86° E), India, serum 25(OH)D was measured using enzyme-linked immunosorbent assay. Sunlight exposure was assessed using PSU dosimeter and by questionnaire. Results: Of 160 men (48.3 ± 5.6 years), 26.8% were deficient and 40.6% had insufficient Vitamin D concentrations. A hyperbolic function for the relationship between PSU measured sunlight exposure in standard erythema dose (SED) and serum 25(OH)D concentrations (r = 0.87, P < 0.01) revealed that daily exposure of 1 SED was sufficient to maintain serum 25(OH)D concentrations over 50 nmol/L. The curve plateaued around 5 SED (80 nmol/L) and extrapolation of the curve (>5 SED) did not increase 25(OH)D concentrations above 90 nmol/L. Receiver operating curve analysis confirmed that 1 SED-UV exposure was sufficient to maintain 25(OH)D concentrations over 50 nmol/L. Based on the questionnaire data, >1 h of midday casual sunlight exposure was required to maintain serum 25(OH)D concentrations above 50 nmol/L. Duration of sunlight exposure assessed by questionnaire and PSU dosimeter showed a significant correlation (r = 0.517, P < 0.01). Conclusion: In urban Indian men, >1 h of casual midday sunlight exposure daily was required to maintain serum 25(OH)D concentrations above 50 nmol/L, and >2 h of casual sunlight exposure was needed to maintain 25(OH)D concentrations above 75 nmol/L. Excess sunlight did not increase 25(OH)D linearly. The sunlight exposure questionnaire was validated for use in clinical studies and surveys.


How to cite this article:
Patwardhan VG, Mughal ZM, Chiplonkar SA, Webb AR, Kift R, Khadilkar VV, Padidela R, Khadilkar AV. Duration of casual sunlight exposure necessary for adequate Vitamin D status in Indian Men.Indian J Endocr Metab 2018;22:249-255


How to cite this URL:
Patwardhan VG, Mughal ZM, Chiplonkar SA, Webb AR, Kift R, Khadilkar VV, Padidela R, Khadilkar AV. Duration of casual sunlight exposure necessary for adequate Vitamin D status in Indian Men. Indian J Endocr Metab [serial online] 2018 [cited 2021 Apr 12 ];22:249-255
Available from: https://www.ijem.in/article.asp?issn=2230-8210;year=2018;volume=22;issue=2;spage=249;epage=255;aulast=Patwardhan;type=0