Sunlight exposure is just one of the factors which influence vitamin D status

2017 ◽  
Vol 16 (3) ◽  
pp. 302-313 ◽  
Author(s):  
M. Abboud ◽  
M. S. Rybchyn ◽  
R. Rizk ◽  
D. R. Fraser ◽  
R. S. Mason
Keyword(s):  
Vitamin D ◽  
Sunlight Exposure ◽  
Ultraviolet B ◽  
Vitamin D Status ◽  
Ultraviolet B Radiation

Studies on the determinants of vitamin D status have tended to concentrate on input – exposure to ultraviolet B radiation and the limited sources in food.

scholarly journals Poor Status of Vitamin D: A Survey of Area With Lowest Sunlight Radiation in Sichuan, China

2021 ◽  
Vol 12 ◽  
Author(s):  
Pianpian Fan ◽  
Qin Wang ◽  
Jing Li ◽  
Chunyan Lu ◽  
Yong Xu ◽  
...  
Keyword(s):  
Vitamin D ◽  
Exposure Duration ◽  
Mineral Metabolism ◽  
Vitamin D Supplementation ◽  
Sunlight Exposure ◽  
Ultraviolet B ◽  
Enzyme Linked Immunosorbent Assay ◽  
Adult Women ◽  
Vitamin D Status ◽  
Sunlight Radiation

ObjectiveVitamin D plays an important role in bone and mineral metabolism. Ultraviolet B (UVB) is the primary determinant for vitamin D synthesis. However, population-based data of vitamin D status was sparse in areas with sunlight deprivation in China. This study aimed to assess serum 25-hydroxyvitamin D [25(OH)D] levels among adult women in Sichuan basin with the lowest sunlight radiation in China, and the associations with sunlight exposure and age.MethodsIn the context of the same ethnicity, similar latitude and lifestyle in sunlight-limited basin and sunlight-abundant plateau, 1,057 women in basin and 337 in plateau aged 29–95 years were included in this study, from November 2012 to February 2013. Daily sunlight exposure duration of previous month was obtained using questionnaires. Serum 25(OH)D was measured by enzyme-linked immunosorbent assay.ResultsThe prevalence of vitamin D severe deficiency [25(OH)D <30 nmol/L] and deficiency [30 ≤ 25(OH)D <50 nmol/L] was significantly higher in basin than plateau (21.85% vs. 10.09%, and 59.32% vs. 40.36%; P<0.0001). Women from basin exhibited lower serum 25(OH)D levels than those from plateau (40.66 ± 15.62 vs. 52.54 ± 19.94 nmol/L, P<0.0001). In basin, women more than 50 years old had higher 25(OH)D than younger counterparts, and 25(OH)D level of these groups was not associated with sunlight exposure duration. While in plateau, women younger than 60 years old had higher 25(OH)D than the older women. Furthermore, for those younger groups, women with long sunlight exposure (≥3 h daily) had higher 25(OH)D concentration than those with short sunlight exposure (<3 h daily). Serum PTH was negatively associated with 25(OH)D in basin, but not in plateau.ConclusionsAlarmingly high prevalence of vitamin D deficiency was observed in women in sunlight-deprived basin in Sichuan. Only the vitamin D status of younger women from plateau with adequate solar radiation could benefit from sunlight exposure. Vitamin D supplementation and vitamin D-fortified food should be encouraged to improve vitamin D status for women living in sunlight-limited areas, or with old age.

scholarly journals Vitamin D status in the tropics: Is sunlight exposure the main determinant?

2018 ◽  
Vol 43 (4) ◽  
pp. 428-434 ◽  
Author(s):  
M. M. Mendes ◽  
K. H. Hart ◽  
P. B. Botelho ◽  
S. A. Lanham-New
Keyword(s):  
Vitamin D ◽  
Sunlight Exposure ◽  
Vitamin D Status ◽  
Main Determinant ◽  
The Tropics

scholarly journals Insufficient autumn vitamin D intake and low vitamin D status in 7-year-old Icelandic children

2014 ◽  
Vol 18 (2) ◽  
pp. 208-217 ◽  
Author(s):  
Adda Bjarnadottir ◽  
Asa Gudrun Kristjansdottir ◽  
Hannes Hrafnkelsson ◽  
Erlingur Johannsson ◽  
Kristjan Thor Magnusson ◽  
...  
Keyword(s):  
Vitamin D ◽  
Cardiorespiratory Fitness ◽  
Sunlight Exposure ◽  
Vitamin D Status ◽  
Blood Samples ◽  
Hydroxyvitamin D ◽  
Vitamin D Intake ◽  
School Based ◽  
25 Hydroxyvitamin D ◽  
Vitamin D Supplements

AbstractObjectiveThe aim was to investigate autumn vitamin D intake and status in 7-year-old Icelanders, fitting BMI and cardiorespiratory fitness as predictors.DesignThree-day food records and fasting blood samples were collected evenly from September to November, and cardiorespiratory fitness was measured with an ergometer bike. Food and nutrient intakes were calculated, and serum 25-hydroxyvitamin D (s-25(OH)D) and serum parathyroid hormone were analysed. Suboptimal vitamin D status was defined s-25(OH)D <50 nmol/l, and deficient status as s-25(OH)D <25 nmol/l.SettingSchool-based study in Reykjavik, Iceland in 2006.SubjectsOf the 7-year-olds studied (n 265), 165 returned valid intake information (62 %), 158 gave blood samples (60 %) and 120 gave both (45 %).ResultsRecommended vitamin D intake (10 μg/d) was reached by 22·4 % of the children and 65·2 % had s-25(OH)D <50 nmol/l. Median s-25(OH)D was higher for children taking vitamin D supplements (49·2 nmol/l v. 43·2 nmol/l, respectively; P < 0·0 0 1). Median s-25(OH)D was lower in November (36·7 nmol/l) than in September (59·9 nmol/l; P < 0·001). The regression model showed that week of autumn accounted for 18·9 % of the variance in s-25(OH)D (P < 0·001), vitamin D intake 5·2 % (P < 0·004) and cardiorespiratory fitness 4·6 % (P < 0·005).ConclusionsA minority of children followed the vitamin D recommendations and 65 % had suboptimal vitamin D status during the autumn. Week of autumn was more strongly associated with vitamin D status than diet or cardiorespiratory fitness, which associated with vitamin D status to a similar extent. These results demonstrate the importance of sunlight exposure during summer to prevent suboptimal vitamin D status in young schoolchildren during autumn in northern countries. An increased effort is needed for enabling adherence to the vitamin D recommendations and increasing outdoor activities for sunlight exposure.

scholarly journals Which Environmental Factor Is Correlated with Long-Term Multiple Sclerosis Incidence Trends: Ultraviolet B Radiation or Geomagnetic Disturbances?

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Seyed Aidin Sajedi ◽  
Fahimeh Abdollahi
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Geomagnetic Disturbance ◽  
Ultraviolet B ◽  
Geomagnetic Disturbances ◽  
Incidence Trends ◽  
Ultraviolet B Radiation ◽  
Cross Correlation Analysis ◽  
Positive Correlations

Background. Insufficient received ultraviolet B radiation (UV) is regarded as the main environmental risk factor (RF) for MS in vitamin D deficiency hypothesis. Nevertheless, geomagnetic disturbance (GMD) has also been proposed as a potential trigger for MS in GMD hypothesis. The aim of this study was to investigate which of these mentioned RF is correlated with long-term ultradecadal MS incidence. Methods. After a systematic search, long-term incidence reports of the United Kingdom (UK), Denmark, Tayside County, Nordland County, the Orkney, and Shetland Islands were selected for this retrospective time-series study. Possible lead-lag relationships between MS incidence, GMD, and UV were evaluated by cross-correlation analysis. Results. Significant positive correlations between GMD and MS incidence were seen in Tayside County (at lag of 2 years: rS = 0.38), Denmark (peak correlation at lag of 2 years: rS = 0.53), and UK (at lag of 1 year: rS = 0.50). We found a positive correlation between received UV and MS incidences in the Nordland at lag of 1 year (rS = 0.49). Conclusion. This study found significant positive correlations between alterations in GMD with alterations in long-term MS incidence in three out of six studied locations and supports the GMD hypothesis. The observed significant correlation between MS and UV is positive; hence it is not supportive for UV related vitamin D deficiency hypothesis.

scholarly journals Nutrihealth Study: Seasonal Variation in Vitamin D Status Among the Slovenian Adult and Elderly Population

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1838 ◽  
Author(s):  
Maša Hribar ◽  
Hristo Hristov ◽  
Matej Gregorič ◽  
Urška Blaznik ◽  
Katja Zaletel ◽  
...  
Keyword(s):  
Vitamin D ◽  
Seasonal Variation ◽  
Vitamin D Deficiency ◽  
Elderly Population ◽  
Sun Exposure ◽  
Epidemiological Data ◽  
The Elderly ◽  
Vitamin D Insufficiency ◽  
Ultraviolet B ◽  
Vitamin D Status

Several studies conducted around the world showed substantial vitamin D insufficiency and deficiency among different population groups. Sources of vitamin D in the human body include ultraviolet B (UVB)-light-induced biosynthesis and dietary intake, but people’s diets are often poor in vitamin D. Furthermore, in many regions, sun exposure and the intensity of UVB irradiation during wintertime are not sufficient for vitamin D biosynthesis. In Slovenia, epidemiological data about vitamin D status in the population were investigated through a national Nutrihealth study—an extension to the national dietary survey SI.Menu (2017/18). The study was conducted on a representative sample of 125 adult (18–64 years) and 155 elderly (65–74 years old) subjects, enrolled in the study in different seasons. Their vitamin D status was determined by measuring the serum 25-hydroxy-vitamin D (25(OH)D) concentration. Thresholds for vitamin D deficiency and insufficiency were 25(OH)D levels below 30 and 50 nmol/L, respectively. Altogether, 24.9% of the adults and 23.5% of the elderly were found to be vitamin D deficient, while an insufficient status was found in 58.2% and 62.9%, respectively. A particularly concerning situation was observed during extended wintertime (November–April); vitamin D deficiency was found in 40.8% and 34.6%, and insufficient serum 25(OH)D levels were observed in 81.6% and 78.8%, respectively. The results of the study showed high seasonal variation in serum 25(OH)D levels in both the adult and elderly population, with deficiency being especially pronounced during wintertime. The prevalence of this deficiency in Slovenia is among the highest in Europe and poses a possible public health risk that needs to be addressed with appropriate recommendations and/or policy interventions.

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