Abstract:Urban Asian Indians generally have low serum 25(OH)D. Information on serum bioavailable 25(OH)D and the effect of prolonged sun-exposure in them is not known. We assessed serum 25(OH)D and bioavailable 25(OH)D in males with varying durations of sun-exposure in Delhi during August-September. Serum 25(OH)D, vitamin D-binding protein (DBP), bioavailable 25(OH)D, free 25(OH)D index, iPTH, ionized calcium and sun-index were assessed in outdoor, mixed outdoor-indoor and indoor workers (n = 88, 32 and 74, respectivel… Show more
“…The examples include farmers of Nebraska, coastal guards, field workers in Florida, and countries with plenty sunshine as Hawaii, Israel and Australia, where serum 25(OH)D ranged from 75 to 160 nmol/L . The vitamin D status of traditional hunters in Tanzanian, Caribbeans and Indian construction workers too ranged from 75 to 115 nmol/L …”
Section: Discussioncontrasting
confidence: 73%
“…Interestingly, our recent study showed normal vitamin D status in outdoor construction workers of Delhi . Absence of VDD in the construction workers was explained by compulsory long hours of sun exposure.…”
Background
There is reservation about accepting the notion of widespread vitamin D deficiency (VDD) in sunny countries because information base is largely urban indoors, and the cut‐off serum 25(OH)D > 75.0 nmol/L to define sufficiency is perceived as high.
Objective
We assessed the vitamin D status of subjects engaged in six types of outdoor jobs with freedom to seek shade, when needed.
Design
Descriptive observational study.
Subjects and methods
A total of 573 outdoors, (hawkers, n = 144; auto‐rickshaw drivers, n = 113; manual rickshaw pullers, n = 49; fuel‐station attendants, n = 84; gardeners, n = 96; traffic police personnel, n = 87) were assessed for serum 25(OH)D, iPTH and total calcium during summer and winter. Bank employees were indoor controls (n = 72). Serum 25(OH)D was defined as sufficient if ≥50.0 nmol/L and deficient when <30.0 nmol/L, as per ‘Institute of Medicine’.
Results
Mean serum 25(OH)D of 573 outdoors was 44.8 ± 19.6 nmol/L and showed a physiological inverse relation with iPTH (P < 0.001). 77.5% of the outdoors did not have VDD. Hawkers, gardeners, fuel‐station attendants and rickshaw pullers had sufficient or near sufficient serum 25(OH)D. The mean serum 25(OH)D (30.6 ± 23.2 nmol/L) of indoors though lower by 12.7 nmol/L than outdoors was above the cut‐off of VDD. Proportions with supranormal iPTH were comparable between outdoors and indoors (14.0% vs 20.8%). Despite winter dip, the mean serum 25(OH)D (31.2 ± 14.3 nmol/l) of outdoors was not deficient.
Conclusions
Vitamin D deficiency is not universal. Most urban outdoor workers do not have VDD.
“…The examples include farmers of Nebraska, coastal guards, field workers in Florida, and countries with plenty sunshine as Hawaii, Israel and Australia, where serum 25(OH)D ranged from 75 to 160 nmol/L . The vitamin D status of traditional hunters in Tanzanian, Caribbeans and Indian construction workers too ranged from 75 to 115 nmol/L …”
Section: Discussioncontrasting
confidence: 73%
“…Interestingly, our recent study showed normal vitamin D status in outdoor construction workers of Delhi . Absence of VDD in the construction workers was explained by compulsory long hours of sun exposure.…”
Background
There is reservation about accepting the notion of widespread vitamin D deficiency (VDD) in sunny countries because information base is largely urban indoors, and the cut‐off serum 25(OH)D > 75.0 nmol/L to define sufficiency is perceived as high.
Objective
We assessed the vitamin D status of subjects engaged in six types of outdoor jobs with freedom to seek shade, when needed.
Design
Descriptive observational study.
Subjects and methods
A total of 573 outdoors, (hawkers, n = 144; auto‐rickshaw drivers, n = 113; manual rickshaw pullers, n = 49; fuel‐station attendants, n = 84; gardeners, n = 96; traffic police personnel, n = 87) were assessed for serum 25(OH)D, iPTH and total calcium during summer and winter. Bank employees were indoor controls (n = 72). Serum 25(OH)D was defined as sufficient if ≥50.0 nmol/L and deficient when <30.0 nmol/L, as per ‘Institute of Medicine’.
Results
Mean serum 25(OH)D of 573 outdoors was 44.8 ± 19.6 nmol/L and showed a physiological inverse relation with iPTH (P < 0.001). 77.5% of the outdoors did not have VDD. Hawkers, gardeners, fuel‐station attendants and rickshaw pullers had sufficient or near sufficient serum 25(OH)D. The mean serum 25(OH)D (30.6 ± 23.2 nmol/L) of indoors though lower by 12.7 nmol/L than outdoors was above the cut‐off of VDD. Proportions with supranormal iPTH were comparable between outdoors and indoors (14.0% vs 20.8%). Despite winter dip, the mean serum 25(OH)D (31.2 ± 14.3 nmol/l) of outdoors was not deficient.
Conclusions
Vitamin D deficiency is not universal. Most urban outdoor workers do not have VDD.
“…A recent observational study on adult Indians has documented that sunshine exposure is associated with higher serum 25(OH)D levels [9]. Outdoor manual workers in Delhi had normal vitamin D status with mean serum 25(OH)D values between 20 and 30 ng/mL [9].…”
Section: Vitamin D Sufficiency Through Sunshine Inmentioning
confidence: 99%
“…Outdoor manual workers in Delhi had normal vitamin D status with mean serum 25(OH)D values between 20 and 30 ng/mL [9]. It is possible that the lack of adequate sunshine exposure among mothers and their offspring is resulting in a high prevalence of biochemical vitamin D deficiency.…”
Section: Vitamin D Sufficiency Through Sunshine Inmentioning
“…In another study from north India,[4] authors compared serum 25(OH) D and bioavailable 25(OH) D in males with varying durations of sun-exposure between indoor and outdoor environments in Delhi during August–September. They demonstrated that serum 25(OH)D increases by 2.03 ng/mL per hour of sun-exposure (95% confidence interval 1.77–2.28; P < 0.001).…”
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