Association of vitamin D levels in coal miners: A case–control study

Abstract

Introduction: Coal miners working underground are likely to be at greater risk of developing Vitamin D deficiency due to reduced sunlight exposure. To date, only three studies have been reported, with no significant risk of Vitamin D deficiency among coal miners. None were conducted in the tropical region, where sunlight is ample. Objective: The present study estimated Vitamin D levels among underground coal miners in a tropical region and determined their associated factors. Methods: Serum calcium, 25-hydroxyvitamin D, and bone turnover markers among underground and surface workers were estimated in a matched case–control study. Binary logistic regression analysis was performed using case/control as the dependent variable to estimate odds ratios and 95% confidence intervals of variables which significantly ( P < 0.1) differed among the cases and controls. Results: The mean Vitamin D level among both coal miners (22.12 ng/dl) and surface workers (23 ng/dl) were low. No significant difference was noted for all biochemical parameters after adjusting for other covariates except the parathyroid hormone (PTH), which was marginally higher among the surface workers. Conclusions: Even in the absence of statistically significant evidence of low Vitamin D level in underground workers compared to surface workers, there was indirect evidence (of differences in PTH) to indicate that Vitamin D level is lower in underground workers probably because of poor sunlight exposure.

Vitamin D Status and Its Correlation With Anthropometric and Biochemical Indicators of Cardiometabolic Risk in Serbian Underground Coal Miners in 2016

“…This can additionally explain the difference in VitD status with the urban-living Serbian general male population, not performing hard physical work, in which levels were almost three times lower (49.8 ± 17.2 nmol/L), despite quite similar BMI (28 ± 6.3 kg/m 2 ), waist circumference (98.5 ± 18 cm), and slightly higher FM% (24.8 ± 10.3%) ( 28 ). However, this cannot explain the difference in VitD status with other published data on summer VitD status in coal miners around the world ( 18 – 21 ). The main explanations for the difference with the Newcastle (UK) coal miners [where average values of 73.8 ± 73.4 nmol/L were found during the summer period ( 18 ), which were two times lower compared with these data] are geographic latitude and the lower level of insolation, apart from the earlier time of sampling (from May to July).…”

“…This study is among the very rare ones that examined the levels of VitD in a population of underground coal miners. We found surprisingly high levels of late-summer serum 25 (OH) VitD, which were much higher compared with the same season VitD data on an urban-living, general male Serbian population from similar geographic latitude (28), and previously published values for coal miners from other geographic regions (18)(19)(20)(21).…”

“…The main explanations for the difference with the Newcastle (UK) coal miners [where average values of 73.8 ± 73.4 nmol/L were found during the summer period ( 18 ), which were two times lower compared with these data] are geographic latitude and the lower level of insolation, apart from the earlier time of sampling (from May to July). In the study from India, samples were taken over a whole year, not specified if summer or winter ( 21 ), and in two other studies from UK and Turkey, the samples were from the winter/early spring period ( 19 , 20 ). Nevertheless, the values in all those studies were much lower, particularly in Turkish workers ( 20 ).…”

“…All of those are characteristics of underground mining work. Nevertheless, insufficient data exist on the serum levels of VitD in this population of workers (17)(18)(19)(20)(21), and the data do not show the lower levels compared with the general population or surface workers from the same geographic region (17)(18)(19)(20)(21). Therefore, more data are needed on this topic.…”

Erratum: Association of Vitamin D levels in coal miners: A case–control study

“…In the article titled “Association of Vitamin D Levels in Coal Miners: A Case–Control Study”, by Sanjay Dash, Sandhya Gupta, Venkatarao Epari, Priti Yugma Patra., 0.4103/ijcm.IJCM_269_19 published on pages 181-183, Issue 2, Volume 45 of Indian Journal of Community Medicine [ 1 ], there has been a technical typographical error, in the expression of levels of vitamin – D. It is mentioned as ng/dl, which on the contrary should have been ng/ml.…”