Assessment of sun exposure in adolescent girls using activity diaries

Risk factors of vitamin D deficiency among 15-year-old adolescents participating in the Malaysian Health and Adolescents Longitudinal Research Team Study (MyHeARTs)

Background

This study is to determine the prevalence and risk factors of vitamin D deficiency (vitamin D ≤ 50 nmol/L) among 15-year-old Malaysian adolescents. By identifying potential risk factors, prevention strategies and interventions can be carried out to improve the vitamin D status in adolescents.

Methods and findings

Stratified random sampling design was used to select adolescents from 15 urban and rural secondary schools in Selangor, Perak and Kuala Lumpur, Malaysia. Data collection was carried out from 1^st April 2014 to 30^th June 2014. Information regarding socio-demographic characteristics, sun exposure and sun protective behaviours, clinical data and environmental factors were collected. Blood for total vitamin D was sampled. Descriptive and multivariate logistic regressions were performed. Total 1061 participants were analyzed (62% were female; mean age 15.1 ± 0.4 years). The prevalence of vitamin D deficiency was 33%. Mean vitamin D was lower in female (53 ± 15 nmol), obese (body fat percentage (≥25%^m; ≥33.8%^f) (56 ± 16 nmol/L), Malays (58 ± 18 nmol/L) and Indians (58 ± 15 nmol/L). In multivariate analysis, female (OR = 5.5; 95% CI: 3.4–7.5), Malay (OR = 3.2; 95% CI: 1.3–8.0), Indian (OR = 4.3; 95% CI: 1.6–12.0) and those always wearing long sleeve (OR = 2.4; 95% CI: 1.1–5.4) were more likely to have vitamin D deficiency. For female participants, ethnicity {Malays (OR = 6.7; 95% CI: 2.0–18.5), Indian (OR = 4.5; 95% CI: 1.8–19.3)} was an important risk factors. Cloud cover, school residence, skin pigmentation, sun-exposure and sun-protective behaviours were not significant risk factors. The limitation of this study was recall bias as it relied on self-reported on the sun exposure and protective behaviours. The diet factors were not included in this analysis.

Conclusions

The prevalence of Vitamin D deficiency among Malaysian adolescents was considerable. Gender, ethnicity and clothing style were important risk factors.

Improving Vitamin D Status and Related Health in Young Women: The Safe-D study - Part B

BACKGROUND

Vitamin D deficiency is highly prevalent and associated with increased risk of a number of chronic health conditions including cardiovascular disease, poor bone and muscle health, poor mental health, infection, and diabetes. Vitamin D deficiency affects millions of Australians, potentially causing considerable suffering, economic loss, and mortality.

OBJECTIVE

To measure the effectiveness of a (1) mobile-based app (behavioral) and (2) pharmacological intervention to increase circulating 25-hydroxyvitamin D (serum 25 OHD) levels and health outcomes over 4 months of intervention compared with usual care in a cohort of young women with suboptimal serum 25 OHD levels (25-75 nmol/L).

METHODS

Participants with 25 OHD levels 25 to 75 nmol/L are invited to participate in this study. Participants are randomized to one of three groups in 1:1:1 ratio: a mobile phone-based application, vitamin D supplementation (1000 IU/day), and a control group. Data collection points are at baseline, 4, and 12 months post baseline with the major endpoints being at 4 months. A wide-range of information is collected from participants throughout the course of this study. General health, behavioral and demographic information, medications, smoking, alcohol and other substance use, health risk factors, nutrition, eating patterns and disorders, and mental health data are sourced from self-administered, Web-based surveys. Clinical data include anthropometric measurements, a silicone skin cast of the hand, cutaneous melanin density, bone mineral density, and body composition scans obtained through site visits. Main analyses will be conducted in two ways on an intention-to-treat (ITT) basis using the last observation carried forward approach as an imputation for missing data, and on a per protocol basis to compare the intervention arms against the control group at 4 and 12 months.

RESULTS

Publication of trial results is anticipated in 2017.

CONCLUSIONS

The study will allow assessment of the effects of a mobile-based app behavioral intervention and vitamin D supplementation on vitamin D status and will evaluate the effects of improving vitamin D levels on several health outcomes.

Sunlight exposure assessment: can we accurately assess vitamin D exposure from sunlight questionnaires?

The purpose of this review is to summarize the peer-reviewed literature in relation to sunlight exposure assessment and the validity of using sunlight exposure questionnaires to quantify vitamin D status. There is greater variability in personal ultraviolet (UV) light exposure as the result of personal behavior than as the result of ambient UV light exposure. Although statistically significant, the correlation coefficients for the relation between personal report of sun exposure and ambient UV light measured by dosimetry (assessment of radiation dose) are relatively low. Moreover, the few studies to assess the relation between sunlight measures and serum 25-hydroxyvitamin D show low correlations. These low correlations may not be surprising given that personal factors like melanin content in skin and age also influence cutaneous synthesis of vitamin D. In summary, sunlight exposure questionnaires currently provide imprecise estimates of vitamin D status. Research should be directed to develop more objective, nonintrusive, and economical measures of sunlight exposure to quantify personal vitamin D status.

Occupational exposure to ultraviolet radiation: the duality dilemma

Human exposure to ultraviolet (UV) radiation is a component of everyday life and a significant hazard for outdoor workers. In addition, a large range of artificial sources also has the potential to provide extreme occupational UV exposure. Even though the human health risks of overexposure to UV are well documented, to date relatively little is known quantitatively about UV exposure. For example, the evidence indicates that workers who are exposed to particular sources (for example, welding arcs) are exposed to extreme UV exposures, despite the use of current control measures. In contrast, increasing evidence points to significant health impacts resulting from underexposure to UV, particularly with the production (or more correctly lack of production) of vitamin D in the skin. The latter poses a serious issue for the work-force, with specific risks for workers lacking adequate sun exposure-underground miners, long-haul flight crews, shift workers, and perhaps indoor workers. Using a risk-management approach, this paper provides a comprehensive review of occupational UV sources, health impact of occupational UV exposure, occupational exposure standards, and levels of exposure in various settings, and discusses the appropriate control measures. In addition, the duality aspect of health impacts from overexposure and underexposure to UV and the associated occupational health implications are specifically explored.

Youth solar ultraviolet radiation exposure, concurrent activities and sun-protective practices: a review

To assist standardization of procedures, facilitate comparisons, and help guide research efforts to optimally inform development of appropriately targeted interventions, there is a need to review methods used to quantify child and adolescent solar ultraviolet radiation (UV) exposure, related outdoor activities and sun-protective practices. This holistic approach is essential for comprehensive research that will provide all-inclusive, informative and meaningful messages for preventive measures of harmful UV exposure. Two databases were searched and 29 studies were retrieved, and these studies report measurement or assessment techniques documenting UV exposure patterns and related outdoor activities. Polysulfone film badges were the main measurement instrument used in 10 studies, with questionnaire, survey data, observation, a model, electronic dosimeters, biological dosimeters, colorimeter and UV colouring labels used in the remaining studies. Methods used to record activities included self-report, parental report, a logbook and observation. Measurement duration and unit of UV exposure varied in most studies, but a method common to 15 studies was measured UV exposure as a percentage of ambient UV. The studies reviewed do not provide sufficient information for the development and evaluation of targeted youth sun protection programs. Studies are required which document precise UV exposure, concurrent activities and sun protection usage for children and adolescents.

Adolescent Girls in Maine Are at Risk for Vitamin D Insufficiency

The objective was to determine the seasonal fluctuations in serum 25-hydroxyvitamin D (25-OHD) in a group of healthy adolescents living in a northern climate. Twenty-three 9- to 11-year-old girls participated in the study from September 2000 to March 2003. Serum 25-OHD and parathyroid hormone levels were measured each September and March. Dietary intake of vitamin D was assessed each summer and winter. Summer-sun exposure was evaluated using reports of time spent outdoors. The mean decrease in serum 25-OHD from September to March was 28%. Vitamin D insufficiency (at least one serum 25-OHD level <50 nmol/L) was observed in 11 of 23 (48%) subjects. Four of 23 subjects (17%) exhibited vitamin D insufficiency in both September and March. Mean parathyroid hormone levels increased 4 pg/mL (15%) from September to March. Vitamin D intakes need to be increased in winter at northern latitudes.