Laboratory confirmation of the effect of occupational sun exposure on serum 25-hydroxyvitamin D concentration

Abstract

Vitamin D concentration is known to correlate with various parameters. A major source of vitamin D is synthesis in the skin; thus, the duration of sun exposure is known to correlate with serum vitamin D levels. We compared serum levels of vitamin D between 2 occupational groups in Korea: the fisherman group, the most sun-exposed, and the general occupation group, relatively less sun-exposed. This study was conducted on 140 healthy fishermen and 140 healthy residents with various occupations, all of whom resided in the southernmost region of Korea, from June to August 2016. We compared serum concentrations of 25-hydroxyvitamin D (25(OH)D) in both occupation groups by gender and age and suggested vitamin D reference interval for the region. Mean serum 25(OH)D concentrations in the general occupation and fisherman group were 13.60 ± 6.43 and 23.74 ± 8.88 ng/mL, respectively. Mean serum concentration of 25(OH)D was 1.7 times higher in the fisherman group compared with the general occupation group, which was statistically significant (P < .001). Approximately 98% of subjects in the general occupation group and 78% of subjects in the fisherman group demonstrated either vitamin D insufficiency or deficiency. Calculated serum 25(OH)D reference interval for all subjects in our study was 3.8 to 44.4 ng/mL. Despite exposure to a large amount of sunlight, 78% of subjects in the fisherman group presented with either vitamin D deficiency or insufficiency. By taking laboratory measurements of serum 25(OH)D concentrations in fisherman, who were expected to have the highest vitamin D concentrations in Korea, this study could be epidemiologically useful.

Total 25-hydroxy vitamin D level in cerebrospinal fluid correlates with serum total, bioavailable, and free 25-hydroxy vitamin D levels in Korean population

“…However, there was a significant difference in serum total 25(OH)D concentration according to age group. Based on a recent study published by our group, serum total 25 (OH) D levels are the lowest in the 20s but the highest in the 70s [29]. In the present study, the age group of 18 to 65 years had lower serum total 25 (OH) D levels than the age group of over 65 years, consistent with our previous study [29].…”

Does Vitamin D play a role in the management of Covid-19 in Brazil?

“…The time of year, latitude, skin color, age and use of sunscreen influence skin production 19,4 . The widespread prevalence of hypovitaminosis D can also be attributed to environmental factors, such as air pollution, which reduces sunlight exposure 2,20 .…”

Vitamin D status of healthy coastal fishermen of Bangladesh

“…Higher mean vitamin D level (27.04±7.21 ng/ml) found among the fishermen living in coastal areas compared to levels reported in other categories of people by previous Bangladeshi studies signifies the importance of sun exposure to maintain adequate concentration of serum vitamin D. In a similar study, Lee et al found that healthy fishermen who lived in a coastal city in South Korea had 1.7 times higher mean serum concentration of 25(OH)D compared to the general occupation group (23.74±8.88ng/mL and 13.60 ± 6.43, p<.001) [13]. Despite having an abundant exposure to the sun, 71% of our study population had low vitamin D in terms of levels mentioned in the guideline of Endocrine Society.…”

“…Despite having an abundant exposure to the sun, 71% of our study population had low vitamin D in terms of levels mentioned in the guideline of Endocrine Society. Similarly, the South Korean study reported low vitamin D levels in 78% of healthy coastal fishermen despite adequate sun exposure [13]. In India, 84.9% of the healthy adult population of the coastal regions of Odisha had low vitamin D levels [14].…”