Development and validation of sunlight exposure measurement questionnaire (SEM-Q) for use in adult population residing in Pakistan

Vitamin D Deficiency and Its Association With Vitamin D Receptor Gene Variants Among Malaysian Women With Hypertensive Disorders in Pregnancy: Protocol for a Nutrigenomics Study

BACKGROUND

Vitamin D deficiency has been associated with hypertensive disorders in pregnancy (HDP). The risk of developing HDP was reported to be further augmented among individuals with a vitamin D receptor (VDR) genetic variant. However, the reported roles of VDR variants in hypertensive disorders are inconsistent among different populations. Given the relatively higher incidence of vitamin D deficiency among Malaysian pregnant women and the high incidence of HDP in this population, we hypothesize that there may be associations between the risk of vitamin D deficiency and HDP with VDR genetic variants.

OBJECTIVE

This paper outlines the protocol for a study to determine the association of vitamin D status and VDR sequence variants among Malaysian pregnant women with HDP.

METHODS

This prospective study consists of two phases. The first phase is a cross-sectional study that will entail gathering medical records, a questionnaire survey, and laboratory testing for vitamin D status, with a planned recruitment of 414 pregnant women. The questionnaire will be utilized to assess the risk factors for vitamin D deficiency. The vitamin D status will be obtained from measurement of the vitamin D (25-hydroxyvitamin D3) level in the blood. The second phase is a case-control study involving a Malay ethnic cohort with vitamin D deficiency. Participants will be divided into two groups with and without HDP (n=150 per group). Genomic DNA will be extracted from the peripheral blood monocytes of participants using the Qiagen DNA blood kit, and VDR sequence variants will be determined using polymerase chain reaction-high-resolution melting (PCR-HRM) analysis. Sanger sequencing will then be used to sequence randomly selected samples corresponding to each identified variant to validate our PCR-HRM results. The VDR genotype and mutation frequencies of BsmI, ApaI, TaqI, and FokI will be statistically analyzed to evaluate their relationships with developing HDP.

RESULTS

As of December 2023, 340 subjects have been recruited for the phase 1 study, 63% of whom were determined to have vitamin D deficiency. In the phase 2 study, 50 and 22 subjects have been recruited from the control and case groups, respectively. Recruitment is expected to be completed by March 2024 and all analyses should be completed by August 2024.

CONCLUSIONS

The outcome of the study will identify the nonmodifiable genetic components contributing to developing vitamin D deficiency leading to HDP. This will in turn enable gaining a better understanding of the contribution of genetic variability to the development of HDP, thus providing more evidence for a need of customized vitamin D supplementation during pregnancy according to the individual variability in the response to vitamin D intake.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05659173; https://clinicaltrials.gov/study/NCT05659173.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/53722.

Reliability and validity of the Chinese version of the sunlight exposure questionnaire

Objective

This study aimed to translate and validate the reliability and validity of the Chinese version of the Philippines Sunlight Exposure Questionnaire.

Methods

A total of 392 Chinese individuals aged at least 18 years, residing in various cities in Sichuan province for at least 1 year, were recruited. The reliability of the Chinese version of the questionnaire was measured through internal consistency, split-half reliability, and retest reliability, while validity was determined using the content validity index and the structure validity index.

Results

The Chinese version of the Sunlight Exposure Questionnaire, which includes 19 items covering 5 factors, demonstrated McDonald's omega coefficient of 0.788. The split-half reliability of the questionnaire was 0.823, and the retest reliability was 0.940. The content validity index (S-CVI) was 0.952. The five-factor structure, supported by eigenvalues, explained 66.2% of the total variance. Confirmatory factor analysis indicated favorable model fit.

Results

The chi-square value degrees of freedom ratio (χ2/df) = 1.852, the goodness-of-fit index (GFI) = 0.938, the normed fit index (NFI) = 0.922, the incremental fit index (IFI) = 0.962, the comparative fit index (CFI) = 0.962, the Tucker-Lewis index (TLI) = 0.952, and root mean square error of approximation (RMSEA) = 0.047. The indicators of the fit of the model were within reasonable bounds.

Conclusion

The Chinese version of the Sunlight Exposure Questionnaire shows validity and good reliability for assessing sun exposure among adults in a Chinese cultural context.

Association of sunlight exposure with visual impairment in an Indian fishing community

Purpose

Indian fishermen belong to a marginalized population and are continuously exposed to extreme occupational hazards and sunlight. A high prevalence of visual impairment (VI) is reported in the coastal fishing community. We aimed to investigate the association between VI and sunlight exposure measurement (SEM).

Methods

In this cross-sectional observational study, 270 eyes of 135 participants were enrolled from a coastal fishing village. Participants underwent a comprehensive ophthalmic examination, which included best-corrected visual acuity (BCVA), and anterior and posterior segment examination. Ocular Surface Disease Index (OSDI) and SEM questionnaire were administered to estimate the level of dry eye and ultraviolet-B (UV-B) exposure, respectively. VI was defined as presenting visual acuity worse than 6/12 (logarithm of the minimum angle of resolution [logMAR] > 0.3).

Results

The mean age and spherical equivalent were 50.56 ± 11.72 years (range: 18-80 years) and 0.36 ± 1.68 diopters (D) (range: -7.0 to +3.0 D), respectively. Age, SEM, OSDI, fishing as an occupation, and cataract were significantly associated with higher odds of VI in univariate analysis. Refraction, gender, education level, smoking status, amblyopia, systematic, and other ocular diseases were not significantly associated with VI. In the multivariate analysis, age, SEM, and presence of cataract remained significantly associated with a higher risk for VI. The area under the receiver operating characteristic curve values for age and SEM scores demonstrate a fair index of discrimination for the detection of VI.

Conclusion

SEM level is directly associated with a higher risk of VI among fishermen. The fishing community might benefit from regular eye examinations and awareness about the harmful effects of sunlight exposure and preventive measures.

Physical Activity, Sun Exposure, Vitamin D Intake and Perceived Stress in Italian Adults

The last decades of global development have, due to rapid urbanization, pressuring entire populations to changes in lifestyle and dietary habits, led to an increase in the prevalence of mental disorders, including stress. This study explored how lifestyle and dietary factors, such as physical activity, sun exposure, and vitamin D intake are related to perceived stress in a Mediterranean-based population. Physical activity level was evaluated using the international physical activity questionnaires (IPAQ), sun exposure was evaluated using the sunlight exposure measurement questionnaire (SEM-Q), and validated food frequency questionnaires (FFQs) were used to assess dietary intakes. The perceived stress of the study participants was evaluated using the perceived stress scale (PSS). Multivariate logistic regression models were used to test for potential associations. In the most adjusted model, an inverse association between physical activity level, sunlight exposure, vitamin D intake, and high perceived stress was found (OR = 0.72, 95% CI: 0.51, 1.00, OR = 0.72, 95% CI: 0.52, 0.99, OR = 0.69, 95% CI: 0.53, 0.89, respectively). However, when stratifying the population by level of physical activity, the retrieved associations with sunlight exposure and dietary vitamin D intake were significant only among those individuals reporting being moderately to highly physically active (OR = 0.16, 95% CI: 0.08, 0.33 and OR = 0.46, 95% CI: 0.28, 0.76, respectively), while results on low physically active participants were null. In conclusion, this study demonstrated that higher dietary intake of vitamin D and sunlight exposure are associated with a lower likelihood of having high perceived stress among physically active individuals.

Development and Validation of Vitamin D- Food Frequency Questionnaire for Moroccan Women of Reproductive Age: Use of the Sun Exposure Score and the Method of Triad's Model

This cross-sectional study aimed to develop and validate a vitamin D food frequency questionnaire (VitD-FFQ) to assess vitamin D intake in Moroccan women of reproductive age. Using the method of triads, the VitD-FFQ was validated against seven-day dietary records (7d-FR) and 25-hydroxyvitamin D (25(OH)D) as a biomarker of vitamin D status in 152 women (aged 18-45 years). Participants' sun exposure scores (SES) were assessed using a specific questionnaire (SEQ). Predictors of vitamin D status were identified via linear regression models. Several statistical tests were applied to evaluate the criterion validity of the FFQ against two references methods (7d-FR and the biomarker-serum 25(OH)D). Median (Interquartile range) intakes were 7.10 ± 6.95 µg /day and 6.33 ± 5.02 µg/ day, respectively, for VitD-FFQ and 7d-FR. Vitamin D status was mainly determined by SES (R = 0.47) and vitamin D absolute food intakes derived by the VitD-FFQ (R = 0.56), which demonstrated a more significant prediction ability compared to 7d-FR (R = 0.36). An agreement was observed between the VitD-FFQ and 7d-FR (BA index of 3.29%) with no proportional bias (R² = 0.002, p = 0.54). <10% of participants were incorrectly classified, and weighted kappa statistics showed that VitD-FFQ had an acceptable ranking ability compared to the 7d-FR and the biomarker. The validity coefficient for the VitD-FFQ was high: ρQR = 0.90 (95%CI: 0.89-0.92), and a range from 0.46 to 0.90. Adjustment for the participants' SES and BMI (body mass index) improved the biomarker's validity coefficient (ρRB 0.63 (95% CI 0.39-0.82). Our results indicate that the VitD-FFQ is valid for estimating absolute vitamin D intake in Moroccan women of reproductive age.

Sun Exposure Score and Vitamin D Levels in Moroccan Women of Childbearing Age

Sunlight exposure is an essential source of vitamin D for many humans. However, hypovitaminosis D is a global public health problem. This study aimed to develop and validate a sun exposure score (SES) and correlate it with serum 25-hydroxyvitamin D levels in women of childbearing age. One hundred and sixty women aged 18 to 45 years residing in Meknes, Morocco, were included. A questionnaire estimating the sun exposure score and blood analysis of serum 25-OHD concentration were performed. The questionnaire's reliability and construct validity were evaluated using Cronbach's alpha and factor analysis. Spearman's test was used to assess the correlation between SES and 25-OHD levels. The score's reliability and construct validity were good, with Cronbach's alpha values >0.70 and factorial saturation ranging from 0.696 to 0.948. Serum 25-OHD levels were significantly associated with the total sun exposure score, and all SES domains (Rho was 0.615 (p < 0.0001), 0.307 (p < 0.0001), 0.605 (p < 0.0001), and 0.424 (p < 0.0001) for total SES, indoor exposure domain, outdoor exposure domain, and sun protection practice domain, respectively). In addition, median 25-OHD levels increased significantly when sun exposure was changed from insufficient to sufficient (p < 0.0001). The results suggest that the sun exposure score could be used as a clinical tool to assess vitamin D levels in women of childbearing age.

Vitamin D knowledge and sun exposure practices among Sri Lankan healthcare undergraduates

INTRODUCTION

Although overexposure to ultraviolet radiation may lead to skin cancer, inadequate exposure results in vitamin D deficiency (VDD). We explored vitamin D-related knowledge and sun exposure practices among Sri Lankan healthcare undergraduates.

METHODS

The sampling frame consisted of medical and allied health undergraduates in a single centre. A newly developed, pre-piloted, self-administered questionnaire collected data on vitamin D knowledge, sun avoidance behaviour and outdoor time. Univariate and multivariate logistic regression analysis examined the factors related to outdoor time.

RESULTS

A total of 482 were included in the analysis. The mean (SD) vitamin D knowledge score (0-100% scale) was 31.3% (18%). Only 17.8% scored ≥50% for knowledge. At least one sun avoidance measure was used by 59.3% of the undergraduates. A lower knowledge score was observed with a higher number of sun-avoidance behaviour (mean difference 0.84, p = 0.03). The majority (66%) spent outdoors <30 minutes per day between 9 am-3 pm. The odds of having low outdoor time were 1.6 higher for the female sex (OR:1.61, 95%CI:1.039, 2.492, p<0.001) and studying in the final year (OR:1.63, 95%CI:1.020, 2.602, p = 0.04). Medical students had a higher likelihood of low outdoor time (OR:0.55, 95%CI: 0.361, 0.835, p = 0.005).

CONCLUSIONS

The healthcare undergraduates had low vitamin D knowledge and outdoor time while having increased sun avoidance. Gender, course of study, and academic year appeared to affect outdoor time. Support and guidance should improve knowledge and sun exposure habits that suit academic work and lifestyle in this population. Also, universities can actively promote positive sun exposure by organizing outdoor events.

Assessment of sunlight exposure across industries and occupations using blood vitamin D as a biomarker

Objective

Exposure to ultraviolet (UV) radiation from sunlight induces the production of essential vitamin D, whereas overexposure to sunlight leads to skin cancer. Sunlight exposure has been measured using questionnaires, dosimeters, and vitamin D levels. Several studies have measured vitamin D in the working population; however, these studies were limited to certain occupations such as farmers and construction workers. In the present study, we evaluated sunlight exposure using blood vitamin D as an exposure surrogate across industries and occupations.

Methods

The Korea National Health and Nutrition Examination Survey (KNHANES) is a nationwide study representing the Korean population. We analyzed data from KNHANES between 2008 and 2009. We examined the association between vitamin D levels and pertinent personal, seasonal, residential, and occupational factors. Furthermore, we developed a multiple regression model with factors other than occupational factors (industry and occupation) and obtained residual values. We computed the third quartile (Q3) of the residuals and then calculated the fractions exceeding the Q3 level for each combination of industry and occupation.

Results

Age, sex, body mass index, year, season, latitude, living area, living in an apartment, industry, and occupation were significantly associated with vitamin D levels. Based on the exceeding fraction, the armed forces showed the highest exceeding fraction level of 0.71.

Conclusions

Our results present the high exposure groups to sunlight across industries and occupations. Our results may provide a source for prioritizing occupational groups with a high risk of adverse health effects from sunlight exposure.

Frequency and determinants of vitamin D deficiency among premenopausal and postmenopausal women in Karachi Pakistan

Background

Vitamin D deficiency is becoming a serious public health problem, even in sun-drenched cities like Karachi, Pakistan. We investigated the prevalence of vitamin D deficiency and its association with sociodemographic characteristics, anthropometric measures, and lifestyle factors among premenopausal and postmenopausal women (n = 784).

Methods

Face-to-face interviews were conducted to collect information and serum concentrations of 25-hydroxyvitamin D were measured after the interviews.

Results

A total of 57% of women were vitamin D deficient with higher vitamin D deficiency found among premenopausal women (64.7%) compared to postmenopausal women (49%). The median serum concentrations of 25-hydroxyvitamin D (IQR) were 16.7 ng/ml (IQR 9.8–30.0). Factors associated with vitamin D deficiency were lower socioeconomic status (OR 2.00; 95% CI 1.15–3.48), younger age with highest vitamin D deficiency found in < 35 years of age group (OR 3.11; 95% CI 1.76–5.51), and winter season (OR 1.51, 95% CI 1.07–2.15) after adjusting for multiple confounders. The use of vitamin D supplement (OR 0.59, 95% CI 0.38–0.92) and vigorous exercise (OR 0.20, 95% CI 0.05–0.80) were protective against vitamin D deficiency.

Conclusions

The study shows a high prevalence of vitamin D deficiency, with detrimental health effects, among younger women belonging to lower socioeconomic status and during the winter season. The use of vitamin D supplements and vigorous exercise were protective measures. Public health campaigns are needed for education and awareness about vitamin D deficiency to improve vitamin D status for younger women living in poor environments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-021-01339-9.

Influence of estrogen exposure on systemic lupus erythematosus in Bangladeshi women: a case-control study scenario

Purpose

This study was conducted to find out the association between estrogen exposure and systemic lupus erythematosus (SLE) in Bangladeshi women.

Design/methodology/approach

A case-control study was carried out from January to December 2015 among 128 intervention cases and 128 age-matched control group participants to find out the association with estrogen exposure and development of SLE.

Findings

Case group participants were five times (OR 5.14, 95% CI 2.14–12.33), three times (OR 3.40, 95% CI 1.25–9.21) and four times (OR 4.00, 95% CI 1.45–11.00) more likely to receive different higher levels of education compared to the control group. Exposure to estrogen showed a positive association with the development of SLE. The case group (12.63 ± 1.61 years) had a lower age at menarche than that of the control group (13.31 ± 1.47 years; p < 0.001) and their proportion (62.6%) of using oral contraceptive pills were more than that of the control group (45.6%; p < 0.01). After controlling the effect of the positively associated variables, SLE patients were found two times (adjusted OR 2.26; 95% CI 1.29–3.95) more likely to use oral contraceptive pills than the control group. The case group was more (adjusted OR 0.771; 95% CI 0.642–0.927) prone to have an earlier age at menarche compared to the control group.

Originality/value

This study identified the association between estrogen exposure and SLE. Contraceptive pills should be used cautiously and both consumers and service providers need to be aware of their effects.

Association of sunlight exposure with 25-hydroxyvitamin D levels among working urban adult Filipinos

Objectives

To determine the association of different levels of sunlight exposure, measured using the Filipino sunlight exposure questionnaire (SEQ) with 25-hydroxyvitamin D (25-OHD) levels among working urban adult Filipinos.

Methods

Seventy-five adult participants, living and working in Metro Manila, for at least 1 year, were grouped according to their perceived sunlight exposure pattern: low sunlight exposure (mostly indoor work); moderate sunlight exposure (both indoor and outdoor work); and high sunlight exposure (mostly outdoor work). After completion of the self-administered Filipino SEQ, they underwent serum 25-OHD level determination. Strength of correlation between the SEQ scores and 25-OHD levels was computed.

Results

Serum 25-OHD levels generally increased with increasing sunlight exposure levels. The overall Pearson’s correlation between the SEQ scores and 25-OHD levels of the participants was 0.396 (P = 0.001). The correlation for the individual domains was 0.342 for intensity of sunlight exposure (P = 0.003), 0.321 for factors affecting sunlight exposure (P = 0.005), and 0.256 for sun protection practices (P = 0.027).

Conclusions

The sunlight exposure of working urban adult Filipinos, as measured by the Filipino SEQ, has an overall significant, direct and moderate association with serum 25-OHD levels. This Filipino SEQ can serve as a valuable clinical tool for sunlight exposure assessment to identify individuals at risk for vitamin D deficiency.

A multicenter case control study of association of vitamin D with breast cancer among women in Karachi, Pakistan

Background

The prevalence of vitamin D inadequacy and breast cancer are both high among women living in Karachi, Pakistan.

Methods

A matched case control study was conducted in two hospitals of Karachi, Pakistan to evaluate the association of vitamin D (serum 25-hydroxyvitamin D) concentrations, vitamin D supplementation and sun exposure with breast cancer among Pakistani women. A total of 411 newly diagnosed histologically confirmed primary breast cancer cases were enrolled and 784 controls, free of breast and any other cancers, were matched by age (year of birth ± 5 years), residence in the same geographic area and study site. Information was collected on sociodemographic history, history of vitamin D supplementation, past medical and obstetrical history, family history of breast cancer, sun exposure history, histopathology reports and anthropometric measurement and venous blood was collected to measure serum 25-hydroxyvitamin D (25(OH)D) concentration.

Results

Compared to patients with sufficient serum vitamin D (>30 ng/ml), women with serum vitamin D deficiency (<20ng/ml), had a higher risk of breast cancer (OR = 1.65, 95%CI: 1.10, 2.50). Women with history of vitamin D supplementation one year prior to enrollment, had significant protective effect against breast cancer (OR = 0.32, 95% CI: 0.24, 0.43).

Conclusions and recommendation

Serum vitamin D deficiency was associated with increased risk of breast cancer, while vitamin D supplementation was associated with decreased risk of breast cancer. In Pakistani women, where vitamin D deficiency is common, raising and maintaining serum vitamin D at population level is a safe and affordable strategy. It may play a role in reducing the incidence of both vitamin D deficiency and breast cancer, particularly among poor women where the breast cancer mortality is highest due to limited resources for early detection, diagnosis, and treatment. The effects of vitamin D with regard to breast cancer risk in Karachi Pakistan should be further evaluated.

Association of serum vitamin D status with dietary intake and sun exposure in adults

BACKGROUND & AIMS

Serum 25(OH)D deficiency is becoming an epidemic. The aim was to assess vitamin D status of the adult Greek population in relation to intake, sun exposure and other factors, using data from the Hellenic National Nutrition and Health Survey (HNNHS).

METHODS

Data from 1084 adult participants (37.8% males) were analyzed. Vitamin D intake was assessed using 24-h recalls. Serum 25(OH)D concentration was evaluated and related to anthropometric measurements and other covariates including supplements used, by sex. Variables significantly associated with 25(OH)D < 20 ng/ml were assessed using simple and multiple logistic regression.

RESULTS

Median vitamin D intake from food was 1.23 mcg/day (0.60, 2.44), with 9.1% consuming supplements. Median serum 25(OH)D was 16.72 ng/ml, with no sex differences (P = 0.923). The odds of having 25(OH)D < 20 ng/ml significantly decreased with being very active (OR 0.55, 95% CI 0.35, 0.98), increasing length of sun exposure [1-3 h/day (OR 0.59, 95% CI 0.44, 0.80), >3 h/day (OR 0.36, 95% CI 0.24, 0.55)], and skin colour [light to medium skin (OR 0.47, 95% CI 0.24, 0.91), fairly dark skin colour (OR 0.34, 95% CI 0.17, 0.67) and dark or very dark skin colour (OR 0.34, 95% CI 0.15, 0.75)], compared to respective baseline levels. The odds significantly increased with obesity (OR 1.95, 95% CI 1.24, 3.08), and spring season of blood sample collection (OR 1.75, 95% CI 1.22, 2.50).

CONCLUSIONS

Vitamin D deficiency is highly prevalent in Greek adults. Relevant public health policies are highly recommended, which could include vitamin D fortification. and suggestion for increased but safe sun exposure.

Higher vitamin D levels in Nigerian albinos compared with pigmented controls

BACKGROUND

Several studies have suggested that the lower vitamin D levels in blacks is attributable to the effect of increased pigmentation in blocking cutaneous ultraviolet (UV)-mediated production of vitamin D. Albinos are devoid of melanin and should invariably have higher vitamin D levels when compared with their pigmented counterparts. However, strict photoprotection required in their medical management has been shown to reduce UV-dependent vitamin D production. Associations between low vitamin D and several diseases suggest that the pattern of vitamin D in the black African albino be investigated.

OBJECTIVE

To compare the vitamin D levels between albinos and normal pigmented controls in Anambra State, Nigeria, and thus highlight the impact of skin pigmentation and sun protection practices on vitamin D levels.

METHODOLOGY

This was a cross-sectional study of a consecutive series of albinos from the Albino Foundation, Anambra State. The vitamin D levels of 61 albinos and 58 matched pigmented controls were analyzed. The sun exposures of the participants were calculated using validated sun exposure questionnaires.

RESULTS

The albinos had significantly higher vitamin D levels (median 95.9 [50.1-177.4] ng/ml) than the controls (78.2 [12.1-250] ng/ml). None of the albinos had low vitamin D levels. None of the sun protection practices had significant effects on vitamin D levels.

CONCLUSION

This study contests the claim that black Africans including albinos have low vitamin D levels. Albinos living in South East Nigeria have significantly higher vitamin D levels than their pigmented counterparts.

Development and validation of a sunlight exposure questionnaire for urban adult Filipinos

OBJECTIVES

To develop and validate a self-reported sunlight exposure questionnaire (SEQ) for urban adult Filipinos.

METHODS

The study included adults (19-76 years old) in Metro Manila, Philippines, well-versed in the Filipino (Tagalog) language and had resided in Metro Manila for at least 1 year. Exclusion criteria included pregnancy, active skin disorders, and immunocompromised states. An expert panel created a questionnaire in Likert-scale format based on a conceptual framework and 4 existing instruments. The study proceeded in 4 phases: questionnaire item development, translation and back-translation, pretesting, and construct validity and reliability testing using factor analysis, the Cronbach alpha coefficient, and the paired t-test.

RESULTS

A 25-item, self-administered, Filipino (Tagalog) SEQ answerable using a 4-point Likert scale was created. The questionnaire was administered to 260 adult participants twice at a 2-week interval, with all participants completing both the first and second rounds of testing. All questionnaire items possessed adequate content validity indices of at least 0.86. After factor analysis, 3 questionnaire domains were identified: intensity of sunlight exposure, factors affecting sunlight exposure, and sun protection practices. Internal consistency was satisfactory for both the overall questionnaire (Cronbach alpha, 0.80) and for each of the domains (Cronbach alpha, 0.74, 0.71, and 0.72, respectively). No statistically significant differences were observed in the responses between the first and second rounds of testing, indicating good test-retest reliability.

CONCLUSIONS

We developed a culturally-appropriate SEQ with sufficient content validity, construct validity, and reliability to assess sunlight exposure among urban adult Filipinos in Metro Manila, Philippines.

Duration of Casual Sunlight Exposure Necessary for Adequate Vitamin D Status in Indian Men

OBJECTIVES

To investigate the duration of casual sunlight ultraviolet-B (UVB) exposure required to maintain optimal Vitamin D status (25-hydroxyvitamin-D [25(OH)D]) >50 nmol/L in urban Indian men, using polysulfone (PSU) dosimeters and a sunlight exposure questionnaire.

METHODS

In healthy men (aged 40-60 years) from Pune (18.52° N, 73.86° E), India, serum 25(OH)D was measured using enzyme-linked immunosorbent assay. Sunlight exposure was assessed using PSU dosimeter and by questionnaire.

RESULTS

Of 160 men (48.3 ± 5.6 years), 26.8% were deficient and 40.6% had insufficient Vitamin D concentrations. A hyperbolic function for the relationship between PSU measured sunlight exposure in standard erythema dose (SED) and serum 25(OH)D concentrations (r = 0.87, P < 0.01) revealed that daily exposure of 1 SED was sufficient to maintain serum 25(OH)D concentrations over 50 nmol/L. The curve plateaued around 5 SED (80 nmol/L) and extrapolation of the curve (>5 SED) did not increase 25(OH)D concentrations above 90 nmol/L. Receiver operating curve analysis confirmed that 1 SED-UV exposure was sufficient to maintain 25(OH)D concentrations over 50 nmol/L. Based on the questionnaire data, >1 h of midday casual sunlight exposure was required to maintain serum 25(OH)D concentrations above 50 nmol/L. Duration of sunlight exposure assessed by questionnaire and PSU dosimeter showed a significant correlation (r = 0.517, P < 0.01).

CONCLUSION

In urban Indian men, >1 h of casual midday sunlight exposure daily was required to maintain serum 25(OH)D concentrations above 50 nmol/L, and >2 h of casual sunlight exposure was needed to maintain 25(OH)D concentrations above 75 nmol/L. Excess sunlight did not increase 25(OH)D linearly. The sunlight exposure questionnaire was validated for use in clinical studies and surveys.

Inadequate sunlight exposure in patients with inflammatory bowel disease

OBJECTIVE

Inadequate sun exposure impairs vitamin D activity and favors low bone density, especially in patients at increased risk for osteoporosis, such as those affected by inflammatory bowel disease (IBD). In this study, sun exposure was investigated in a large series of patients with IBD in a Mediterranean country, Italy, where this risk is considered less likely to occur than in higher latitudes.

METHODS

This is a case-control study of 292 patients with IBD [132 with Crohn's disease (CD) and 160 with ulcerative colitis (UC)], 80 diseased and 540 healthy controls, conducted via a validated questionnaire to quantify sunlight exposure. Data were also compared with controls matched by age and gender.

RESULTS

In total 78 of the 292 patients with IBD had low, 169 had moderate and 45 had high exposure to sunlight, significantly differing from controls (P < 0.001). The 132 patients with CD were more likely to have abnormal levels of sunlight exposure (49 low, 72 moderate and 11 high) than those with UC (29 low, 97 moderate and 34 high) (P < 0.001). The controls were significantly more exposed to sunlight than both men and women with IBD (P < 0.001 and 0.004, respectively).

CONCLUSIONS

IBD patients are significantly less exposed to sunlight than matched controls in Italy, often to an extent that may impair vitamin D activation. Increasing responsible sunlight exposure, thus promoting adequate vitamin D concentrations, may prove beneficial in IBD, in geographical areas in which this risk factor is not generally taken into consideration.

Attitudes, Behaviors and Beliefs of Urban Adult Filipinos on Sunlight Exposure: A Qualitative Study

Objective

To explore the attitudes, behaviors, and beliefs of urban adult Filipinos on sunlight exposure as an initial step in the development and validation of a culturally-appropriate questionnaire.

Methodology

Focus groups were conducted among urban Filipinos 19 years old and above (n=38). The transcribed results underwent qualitative content and thematic analyses and were used to develop a conceptual framework.

Results

Qualitative analysis revealed four main themes of sunlight exposure: internal influences, external influences, perceived benefits, and perceived risks. Both internal and external influences lead to perceived risks and benefits. Consequently, the perceived benefits (or lack) of sunlight exposure influence an individual’s attitude towards vitamin D supplementation; whereas the perceived risks of sunlight exposure influence an individual’s attitude towards the need for sun protection.

Conclusion

The attitudes, behaviors and beliefs of urban adult Filipinos on sunlight exposure are influenced by both internal and external factors, that in turn lead to perceived risks and benefits. An increased awareness of these factors is necessary to establish future recommendations on proper sunlight exposure in this population. The study results will be used to develop and validate a culturally-appropriate sunlight exposure questionnaire.

The Mediterranean healthy eating, ageing, and lifestyle (MEAL) study: rationale and study design

There is accumulating evidence suggesting that Mediterranean lifestyles, including nutrition and sleeping patterns as well as social integration, may play a role in reducing age-related diseases. However, the literature is mostly deficient of evidence provided by Italian Mediterranean islands that more closely adhered to the originally described lifestyles. In this paper, we described the rationale and the study design of the Mediterranean healthy Eating, Ageing, and Lifestyle (MEAL) study, a prospective population-based cohort established in Sicily, southern Italy. The main exposures investigated are classical determinants of health, including demographic, nutritional habits, smoking and physical activity status, as well as eating-related behaviors, sleeping habits, sun exposure, social resources, and perceived stress. Anthropometric measurements will be collected. The main outcomes included depression, quality of life, and, after the follow-up period, also cardiovascular disease and cancer. The MEAL study may provide important data to increase our knowledge regarding the prevalence, incidence, and risk factors of age-related disorders in the Mediterranean region.

Prevalence of Vitamin D deficiency in Pakistan and implications for the future

BACKGROUND AND AIMS

vitamin D deficiency (25-hydroxyvitamin D) affects over one billion people worldwide. Vitamin D deficiency results in progression of osteoporosis as well as other conditions. Previous studies have shown high rates of vitamin D deficiency in Pakistan despite appreciable levels of sunshine. However, none have assessed vitamin D deficiency across all age groups, genders, incomes, and locations to guide future strategies.

METHODS

Questionnaire and blood sampling among 4830 randomly selected citizens.

RESULTS

High levels of deficiency among all age groups, genders, income levels, and locations. Amongst the selected citizens, 53.5% had vitamin D deficiency, 31.2% had insufficient vitamin D, and only 15.3% normal vitamin D.

CONCLUSION

High rates of vitamin D deficiency in Pakistan despite high levels of sunshine and previous Food Acts asking for food fortification with vitamin D. Public health strategies are needed to address high deficiency rates, including food fortification, i.e. nurture, alongside increasing exposure to sunlight, i.e. nature. This will involve all key stakeholder groups.

Vitamin D in epilepsy: vitamin D levels in epilepsy patients, patients on antiepileptic drug polytherapy and drug-resistant epilepsy sufferers

The objective of this study was to assess vitamin D levels in epileptic patients and to compare its serum levels in patients on antiepileptic monotherapy and polytherapy. We analyzed the serum 25-hydroxy (25-OH) vitamin D levels in 98 consecutive subjects (43 epileptic patients and 55 non-epileptics). Factors influencing its serum levels such as degree of sun exposure, physical activity and dietary intake were taken into consideration. Overall, 41% had deficient, 49% had insufficient and 9% had sufficient levels of serum vitamin D. Elderly individuals (>60 years) and people employed in offices and schools had lower blood vitamin D levels. Across both the sexes, epileptic patients and non-epileptics, epileptic patients on monotherapy and polytherapy and patients with drug-responsive and -resistant seizures, there were no significant differences in serum 25-OH vitamin D levels. Our study shows that people with epilepsy suffer with vitamin D deficiency along with their normal peers.

Vitamin D intake determines vitamin d status of postmenopausal women, particularly those with limited sun exposure

Few detailed data are available on the wide range of determinants of vitamin D status among postmenopausal women, and it is also unclear whether there may be undiscovered determinants. The objective of this study was to comprehensively evaluate determinants of serum 25-hydroxyvitamin D [25(OH)D] concentrations in a large cohort of postmenopausal women. Data from a subset of the Women's Health Initiative Observational Study were analyzed (50-79 y; n = 3345). Information on diet, lifestyle behaviors, secondhand smoke, use of dietary supplements and medication, chronic diseases, and anthropometry was collected at baseline (1993-1998) and on sun exposure at year 4 follow-up. Linear regression was performed to estimate regression coefficients (β). Significant determinants were total vitamin D intake (food plus supplements per 100 IU/d, β = 2.08), years of supplemental vitamin D use (β = 0.15), total fat intake (grams per day, β = -0.03), smoking status (β = -2.64, current vs. never), regional solar irradiance (β = 6.26, 475-500 vs. 300-325 Langleys), daylight time spent outdoors in summer (β = 5.15, >2 h vs. <30 min/d), recreational physical activity (metabolic equivalent task per hour per week, β = 0.13), waist circumference (centimeters, β = -0.26), and race/ethnicity (β = -11.94, black vs. white). Total vitamin D intake (partial R(2) = 0.09) explained the most variance in serum 25(OH)D concentrations (total R(2) = 0.29). The association between total vitamin D intake and serum 25(OH)D concentrations was stronger among participants who spent less rather than more daylight time outdoors in summer (P-interaction = 0.026). History and medications for hypertension, hyperlipidemia, and type 2 diabetes and secondhand smoke exposure were not associated with serum 25(OH)D. In conclusion, dietary factors and sun exposure remain important determinants of vitamin D status in postmenopausal women. Vitamin D intake should be emphasized for those with limited sun exposure.

Reliability of self-reported sun exposure in Canadian women and estimation of lifetime exposure to vitamin D from sun and diet

OBJECTIVE

To assess the inter-method reliability of the Ovarian Cancer in Alberta (OVAL) survey developed to estimate adult vitamin D exposure from sun and diet for every tenth year, against the longer Geraldton Skin Cancer Prevention Survey (the assumed 'gold standard'). We also estimated total vitamin D exposure using the OVAL survey.

DESIGN

A randomized crossover design to assess the inter-method reliability of sun exposure (OVAL v. Geraldton survey), using intra-class correlation and estimated total vitamin D exposure from sun and diet.

SETTING

Calgary, Alberta, Canada.

SUBJECTS

Randomly selected women (n 90) aged 40-79 years.

RESULTS

The average lifetime sun exposure of 13,913 h (average 411 h/year) from the Geraldton survey was not significantly different from the 13,034 h (average 385 h/year) from the OVAL survey for periods with sufficient UV radiation to stimulate vitamin D production. The intra-class correlation coefficient for average lifetime sun exposure was 0.77 (95% CI 0.69, 0.86); the annual average was 0.60 (95% CI 0.47, 0.74). Estimated vitamin D from diet and supplements increased with age.

CONCLUSIONS

Our OVAL survey reliably estimated adult sun exposure relative to the Geraldton survey, suggesting that assessing sun exposure every tenth year is a reliable and efficient method for estimating sun contributions to lifetime vitamin D exposure.