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Duration of Casual Sunlight Exposure Necessary for Adequate Vitamin D Status in Indian Men
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 (...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Medknow Publications & Media Pvt Ltd
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5972483/ https://www.ncbi.nlm.nih.gov/pubmed/29911040 http://dx.doi.org/10.4103/ijem.IJEM_473_17 |
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author | Patwardhan, Vivek G. Mughal, Zulf M. Chiplonkar, Shashi A. Webb, Ann R. Kift, Richard Khadilkar, Vaman V. Padidela, Raja Khadilkar, Anuradha V. |
author_facet | Patwardhan, Vivek G. Mughal, Zulf M. Chiplonkar, Shashi A. Webb, Ann R. Kift, Richard Khadilkar, Vaman V. Padidela, Raja Khadilkar, Anuradha V. |
author_sort | Patwardhan, Vivek G. |
collection | PubMed |
description | 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. |
format | Online Article Text |
id | pubmed-5972483 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Medknow Publications & Media Pvt Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-59724832018-06-15 Duration of Casual Sunlight Exposure Necessary for Adequate Vitamin D Status in Indian Men Patwardhan, Vivek G. Mughal, Zulf M. Chiplonkar, Shashi A. Webb, Ann R. Kift, Richard Khadilkar, Vaman V. Padidela, Raja Khadilkar, Anuradha V. Indian J Endocrinol Metab Original Article 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. Medknow Publications & Media Pvt Ltd 2018 /pmc/articles/PMC5972483/ /pubmed/29911040 http://dx.doi.org/10.4103/ijem.IJEM_473_17 Text en Copyright: © 2018 Indian Journal of Endocrinology and Metabolism http://creativecommons.org/licenses/by-nc-sa/4.0 This is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms. |
spellingShingle | Original Article Patwardhan, Vivek G. Mughal, Zulf M. Chiplonkar, Shashi A. Webb, Ann R. Kift, Richard Khadilkar, Vaman V. Padidela, Raja Khadilkar, Anuradha V. Duration of Casual Sunlight Exposure Necessary for Adequate Vitamin D Status in Indian Men |
title | Duration of Casual Sunlight Exposure Necessary for Adequate Vitamin D Status in Indian Men |
title_full | Duration of Casual Sunlight Exposure Necessary for Adequate Vitamin D Status in Indian Men |
title_fullStr | Duration of Casual Sunlight Exposure Necessary for Adequate Vitamin D Status in Indian Men |
title_full_unstemmed | Duration of Casual Sunlight Exposure Necessary for Adequate Vitamin D Status in Indian Men |
title_short | Duration of Casual Sunlight Exposure Necessary for Adequate Vitamin D Status in Indian Men |
title_sort | duration of casual sunlight exposure necessary for adequate vitamin d status in indian men |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5972483/ https://www.ncbi.nlm.nih.gov/pubmed/29911040 http://dx.doi.org/10.4103/ijem.IJEM_473_17 |
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