Knowledge of vitamin D and practices of vitamin D supplementation in a Scottish adult population: A cross-sectional study

Background: Vitamin D supplementation practices (dose and frequency) are relatively unknown in the Scottish population, with no recent up-to-date data available. Reassessing current knowledge, practices, and awareness of vitamin D supplementation following a national health campaign in 2020 by Food Standards Scotland on vitamin D is warranted. Aim: This article aims to present the knowledge and awareness of vitamin D, and current vitamin D supplementation practices in adults living in Scotland. Methods: A cross-sectional study was performed between June and July 2022 using an online survey adapted from previous work on assessing knowledge of vitamin D in adults. Participants aged 18+, living in Scotland for ≥6 months were eligible to participate. Scores for knowledge were calculated as a percentage. Univariate associations between demographic and supplement use were established by χ2-test and logistic regression performed to predict factors associated with daily vitamin D intake. Results: Four hundred and three participants (72.7% female), mean age 36.4 (±14.2 years), completed the study. Awareness of vitamin D was very high (99.5%) but the mean overall knowledge score was poor (31.4 ± 15.3%), with those with a university degree more likely to have knowledge scores at/above the mean compared with those with lower levels of education, χ2(1, N = 393) 10.7, p = 0.001, odds ratio (OR) = 2.1 (95% confidence interval (CI) 1.7-2.7). Finally, 64.3% took vitamin D supplements, of which 37.5% took them daily during winter months, with only 7.4% taking the recommended daily dose. Conclusion: The current study highlights the need to improve both knowledge of vitamin D and practices of vitamin D supplementation during the autumn and winter months in Scotland.

Vitamin D levels of pregnant immigrant women and developmental disorders of language, learning and coordination in offspring

BACKGROUND

Prenatal vitamin D deficiency is a common health concern among immigrants. No previous studies have examined the associations between prenatal vitamin D levels and developmental disorders of language, scholastic skills, and coordination in an immigrant sample.

METHODS

The sample included 542 immigrant mothers of cases with language, scholastic, coordination or mixed developmental disorders, 443 immigrant mothers of controls without these disorders and 542 Finnish mothers of controls. Maternal vitamin D was measured in serum samples collected during early pregnancy and stored in a national biobank.

RESULTS

The mean vitamin D levels during pregnancy were 25.0 (SD 14.4) nmol/L for immigrant mothers of cases, 25.4 (SD 15.5) for immigrant mothers of controls and 42.3 (SD 19.1) for Finnish mothers of controls. Low maternal vitamin D levels during pregnancy were not associated with the selected developmental disorders in offspring when immigrant mothers of cases were compared to immigrant mothers of controls (adjusted OR for continuous log-transformed vitamin D: 1.01, 95% CI 0.75-1.36, p = 0.96). When immigrant mothers of cases were compared to Finnish mothers of controls, the adjusted OR for continuous vitamin D was 18.94 (95% CI 11.47-31.25), p <0.001). The results were similar when vitamin D was examined as a categorical variable or divided into quintiles.

CONCLUSIONS

Prenatal vitamin D levels were low, and similar, among immigrant mothers of cases with selected developmental disorders and unaffected controls. This indicates that vitamin D unlikely mediates previously observed associations between maternal immigrant status and the selected developmental disorders in offspring. The proportion of immigrant mothers with severe vitamin D deficiency was very high, which underlines the importance of prenatal counselling and overall public health efforts to improve immigrant health.

Vitamin D: determinants of status, indications for testing and knowledge in a convenience sample of Irish adults

Vitamin D deficiency is common in Irish adults, though there is limited research on its determinants, knowledge of vitamin D or indications for testing. We aimed to explore the determinants of vitamin D status in adults and examine knowledge and reasons for testing. The study population comprised adults who had serum 25-hydroxyvitamin D tested by general practitioners request at a Dublin Hospital in 2020. Questionnaires detailing dietary intake, sun exposure, ethnicity, biophysical factors and vitamin D knowledge were sent to a sample stratified by age, sex and vitamin D status. In total, there were 383 participants, mean age 56·0 (sd 16·6) years. Wintertime deficiency disproportionally affected non-white v. white (60 % v. 24 %, P < 0·001). The greatest predictors of deficiency were low vitamin D intake (< 10 μg/d) (P < 0·001) and non-white ethnicity (P = 0·006), followed by sun avoidance (P = 0·022). It was also more prevalent in those with lower body exposure when outdoors. The majority (86 %) identified vitamin D as important for bone health. However, 40 % were tested for non-clinical indications and half were not aware of the recommended daily allowance (RDA). Low vitamin D intake was the most important determinant of deficiency, but ethnicity and sun exposure habits were also significant predictors. The majority had no clear indication for testing and were not aware of the RDA. Public health policies to improve knowledge and vitamin D intake, especially for those of non-white ethnicity and with reduced sun exposure, should be considered.

Vitamins and minerals, education, and self-care need during preconception to 1000 days of life in Southeast Asia: An expert panel opinion

Addressing maternal malnutrition and its drivers is paramount in Southeast Asia. This article summarizes the key clinical learnings and evidence-based opinions from the experts to understand the need for vitamins and minerals supplementation, education, and self-care from preconception to the first 1000 days of life, which warranted further attention since COVID-19 pandemic. Evidence describing the importance of vitamins and minerals during preconception, pregnancy, and lactation stages was identified using literature databases. A pre-meeting survey was conducted to determine the current practices and challenges in Southeast Asia. Based on the literature review and clinical experience, experts defined the topics, and an online meeting was held on 13th July 2021. During the meeting, nine experts from Southeast Asia provided evidence-based opinion on the vitamins and minerals supplementation, education, and self-care need during preconception, pregnancy, and lactation stages. The expert opinions underpin maternal malnutrition as a prevalent issue and discuss appropriate interventions and prevention strategies for women in Southeast Asia. The recent pandemic further impacted nutrition status, pregnancy, and neonatal health outcomes. The expert panel emphasized a need to improve existing inadequacies in education, self-care, and social support, and discussed the role of policymakers in addressing the barriers to dietary changes. As inadequacies in regular vitamins and minerals supplementation, education, and self-care for women of reproductive age implicate maternal and child health outcomes, there is an urgent need for addressing malnutrition concerns in this population. Thus, a strong partnership between policymakers, healthcare professionals, and other relevant sectors is required.

Knowledge about Vitamin D among Women in the United Arab Emirates

Vitamin D deficiency is a significant public health issue as it affects almost 90% of the United Arab Emirates (UAE) population. A bigger portion of this percentage is women due to the physiological changes throughout their life cycle. This study aims to assess the knowledge about vitamin D among women in the UAE. This is a quantitative cross-sectional study. Using snowball sampling, an electronic questionnaire was sent to women aged 18 years and above. Overall, 1537 women completed the questionnaire. The participants had mean scores of 49.4 ± 10.7 and 59.6 ± 14.6 for general and nutritional knowledge, respectively. Factors associated with higher scores included older age, marriage, higher educational level, and having tested their vitamin D levels. Factors associated with lower scores included the history of a chronic illness and being employed. Findings indicate that women in this study showed a low level of vitamin D knowledge specifically regarding the non-skeletal benefits of vitamin D and factors that affect vitamin D synthesis. Therefore, health education and promotion programs must be implemented across the UAE to improve overall awareness about vitamin D.

Evaluation of Knowledge, Attitudes, and Practices Related to Osteoporosis and Correlates of Perceived High Risk among People Living in Two Main Districts of Lebanon

BACKGROUND

The prevalence of osteoporosis is increasing in Lebanon.

AIM

We evaluated the knowledge, attitudes, and practices related to osteoporosis and correlates of its perceived high risk among people living in Beirut and Mount Lebanon districts of Lebanon.

METHODS

This study is a cross-sectional study which consisted of 376 participants that were selected from the two districts within two or three households after two geographical areas were randomly selected from each stratum classified by education and altitude. They were then asked to fill a KAP survey on osteoporosis and provide information on factors likely related to its perceived high risk.

RESULTS

The majority of participants had a low (20.2%) and moderate (65.4%) knowledge of osteoporosis, with a higher knowledge in females than in males. A higher percentage of young people perceived it as a serious health risk than that of older people. In contrast, 85.9% participants reported drinking caffeinated beverages and 51.6% participants reported that they do not exercise. Glucose intolerance due to epigenetic and genetic factors, female sex, and older age were risk factors of a perceived high risk of osteoporosis, while any physical exercise, abstention from caffeine for 48 to 72 hours, and higher education were protective factors.

CONCLUSION

A nationwide KAP study should be conducted; likewise, awareness campaigns should be adopted.

Knowledge, attitude, performance, and determinant factors of Vitamin D deficiency prevention behaviours among Iranian pregnant women

BACKGROUND

Pregnancy is a high-risk period for vitamin D (Vit D) deficiency, and there is a direct relationship between Vit D deficiency during this period and maternal and fetal complications. Therefore, this study aimed to assess the knowledge, attitude, and practice of pregnant women concerning the adoption of behaviors to prevent Vit D deficiency and identify the determinant factors of such behaviors.

METHODS

In this cross-sectional study, 185 pregnant women with a mean age of 27.52 ± 5.9 years were selected from the Health Centers in Tabriz, Iran, using the stratified random sampling between 2018 September 23 and 2019 June 21. Data were collected using a researcher-made questionnaires comprising demographic information, knowledge, attitude, and practice of pregnant women towards Vit D deficiency. The chi-square test and Fisher's exact test were used to determine the relationship between the demographics of pregnant women and their knowledge and attitude. Moreover, the general linear model test was used to determine the predictors of performance. The p-value< 0.05 was considered to be significant in this study.

RESULTS

The findings showed that 85.6% of pregnant women were well aware of the importance and role of Vit D in pregnancy. In addition, 76.7 and 75% of the participants had good knowledge of getting enough Vit D from sunlight and preventing Vit D deficiency in pregnancy, respectively. Moreover, 91.7% of the pregnant women believed that Vit D has a vital role in maternal and fetal health, and 61.1% showed a high level of perceived self-efficiency in preventing Vit D deficiency. In addition, 67.2% of women regarded the unpleasant taste and price of Vit D rich foods, such as seafood, as barriers to get Vit D, and 91.7% mentioned the lack of public places specific to women and living in apartments as barriers to getting enough Vit D from sunlight. According to the results, 57.8 and 79.4% of pregnant women performed at a moderate level in getting Vit D from food and sunlight, respectively. In general, educational attainment (Pvalue = 0.02, B = 0.56), pregnancy age (Pvalue = 0.04, B = -0.26), parity (Pvalue = 0.03, B = -0.45), and perceived self-efficacy of mothers (Pvalue < 0.001, B = 0.340) were the determinant factors of getting Vit D from food and sunlight as behaviours to prevent Vit D deficiency in pregnancy.

CONCLUSION

The findings of the current study revealed that despite the good knowledge of women about the Vit D deficiency during pregnancy, their performance was moderate. The unpleasant taste and high price of seafood were barriers to using them, and the lack of public places specific to women and living in apartments, were barriers to using sunlight. The most important determinant of preventive behaviours was perceived self-efficacy. Developing an awareness program to promote best practices in pregnant women is essential to prevent vitamin D deficiency.

Evaluation of the knowledge regarding vitamin D, and sunscreen use of female adolescents in Iran

BACKGROUND

Vitamin D (Vit D) deficiency/insufficiency is an important risk factor for several chronic conditions. We aimed to evaluate the knowledge and behavior of female adolescents with respect to the association between sunlight exposure, sunscreen use, and Vit D status.

METHODS

This cross-sectional survey was performed in northeastern Iran, among 940 female adolescents in January 2015. Each subject completed a questionnaire containing items about demographic characteristics, knowledge about Vit D and their use of sunscreen. Serum Vit D levels were measured using an electrochemiluminescence method and dietary intake of Vit D was assessed using a Food Frequency Questionnaire. Statistical analyses were conducted using SPSS software. A P value < 0.05 was considered statistically significant.

RESULTS

Few of the participants were aware of the biological functions of Vit D (8.8%), the causes of Vit D deficiency (16.7%), and the sources of Vit D (9.3%). Less than half of the participants used sunscreen during the day. The serum levels of Vit D in subjects who used sunscreen were significantly lower than those who did not (p = 0.004). However, there was no significant association between their knowledge about Vit D and serum Vit D, or dietary intake of Vit D.

CONCLUSION

There appears to be a lack of coherence between lifestyle, behavior and knowledge that may affect the Vit D status of adolescent girls in northeastern Iran. This information provides a basis for developing public health planning (workshops or training at the college level) for the prevention of Vit D deficiency especially in adolescent girls.

Knowledge and attitudes about vitamin D and sunlight exposure in premenopausal women living in Jeddah, and their relationship with serum vitamin D levels

BACKGROUND

Saudi women are at risk of vitamin D deficiency because they are fully covered by traditional clothing and because of their indoor lifestyle. The latest national study reported that vitamin D deficiency (serum 25(OH)D < 50 nmol/L) affects 72% of young Saudi women. Because little information is available regarding knowledge on vitamin D, attitudes toward sun exposure, and the vitamin D status of premenopausal women in Jeddah, more research is necessary in order to develop effective intervention programs. The purpose of this study is to explore how the relationship between knowledge of vitamin D and attitudes about sun exposure affect the serum 25(OH)D levels in premenopausal Saudi women.

METHODS

This cross-sectional study included 257 women aged 20-50 years attending the primary care clinic in Jeddah, Saudi Arabia. Participants completed questionnaires about socio-demographics, dietary vitamin D intake, attitudes toward sun exposure, and were tested on their knowledge of vitamin D. Serum 25(OH)D was evaluated using chemiluminescent microparticle immunoassay.

RESULTS

Although 99% of participants had heard of vitamin D and 91% knew that sunlight exposure is a primary source of vitamin D, they also expressed the feeling of having insufficient knowledge regarding vitamin D sources. Furthermore, the majority of participants had negative attitudes toward sun exposure. High fish consumption was associated with a higher level of knowledge regarding vitamin D. The binary logistic regression indicated that low levels of knowledge about vitamin D were associated with low education levels (odds ratio = 0.397, 95% CI = [0.206, 0.765], p = 0.019) and with being married (odds ratio = 0.522, 95% CI = [0.281, 0.971], p = 0.04). In addition, spending time outside in the sun was significantly associated with increased serum 25(OH)D levels (p = 0.006), and the wearing of colored abaya was significantly associated with increased serum 25(OH)D levels (p = 0.008).

CONCLUSION

Suboptimal vitamin D status and insufficient knowledge of vitamin D intake sources are common in premenopausal women in Jeddah. Based on this data, health professionals could provide medical intervention to the most vulnerable female patients, as well as offer clear guidelines and information to the general public.

Longitudinal Vitamin D Deficiency Among Malaysian Pregnant Women and Its Correlation With Neonatal Serum 25-Hydroxyvitamin D Levels

Objective: This study aimed to investigate the longitudinal relationship between maternal vitamin D concentrations during pregnancy and neonatal vitamin D concentrations at birth.

Materials and Methods: A prospective cohort of 236 healthy pregnant women from various ethnicity in early pregnancy (≤20 weeks of pregnancy) was followed at late pregnancy (28–40 weeks of pregnancy) and birth. Maternal serum 25-hydroxyvitamin D (25(OH)D) was assessed at early pregnancy (baseline) and late pregnancy, while neonatal cord serum 25(OH)D at birth. General estimating equations (GEE) were used to analyze the longitudinal association of maternal serum 25(OH)D levels during pregnancy and neonatal cord serum 25(OH)D levels at birth with adjusting for the time exposure, maternal weight gain, ethnicity, and skin type.

Results: The results showed that the prevalence of vitamin D deficiency (25(OH)D <50 nmol/L) was at 89.9, 92.2, and 96.1% in early, late pregnancy and in neonatal cord serum, respectively. The GEE analysis showed a trend that longitudinal vitamin D deficiency during pregnancy leads to lower vitamin D concentrations in neonatal cord blood (RR = 1.17; 95% CI (1.05–1.36); p = 0.04).

Conclusion: Longitudinal vitamin D deficiency during pregnancy leads to vitamin D deficiency in neonates at birth. A further trial is needed to affirm this association.

Assessment of knowledge, attitudes and practice towards Vitamin D among university students in Pakistan

Background

Pakistan has one of the highest reported incidence of vitamin D deficiency in studies conducted worldwide. However, there has been very limited exploration of vitamin D related knowledge, attitudes and practices among healthy youth in Pakistan.

Methods

A cross-sectional survey was conducted among youth (aged > 16 years) from two engineering universities in Pakistan. Participants were asked questions on their concern about vitamin D levels, testing, and supplementation practices. Knowledge was examined using questions about food sources, health benefits and factors affecting vitamin D production within the human body. Of the 900 eligible students invited to participate, 505 (56%) completed the questionnaire and were included in the analysis.

Results

Only 9% participants were able to identify the correct food sources of vitamin D, 33% were aware of the bone health benefits (bone health and calcium absorption) of vitamin D and 36% identified sunlight exposure as a factor influencing vitamin D production. Knowledge about food sources and health benefits of vitamin D was not associated with gender and individuals concern about their levels. Those tested and taking supplements were more likely to identify bone related health benefits and factors affecting vitamin D production. Forty percent male and 52% female students expressed concern that their vitamin D levels were too low. However, 72% participants reported that they had never been tested for vitamin D levels. Use of supplements was significantly higher among female students (F = 52% vs M = 37%; P = 0.003). Those who had been tested for vitamin D deficiency were more likely to take supplements.

Conclusion

Despite being identified as a high-risk population, knowledge about vitamin D was limited among university students. Interventions are needed to increase awareness about the importance of vitamin D for health, including the need for exposure to sunlight and adequate dietary intake of vitamin D. Our study provides much needed baseline evidence for making health-policy recommendations for this vulnerable population group.

Disparities in the timing and measurement methods to assess vitamin D status during pregnancy: A Narrative Review

Studies that examined associations between low circulating 25-hydroxyvitamin D (25(OH)D) and adverse pregnancy outcomes used various designs, assay methods and time points for measurement of 25(OH)D concentrations, which creates some confusion in the current literature. We aimed to investigate the variability in the timing and measurement methods used to evaluate vitamin D status during pregnancy. Analysis of 198 studies published between 1976 and 2017 showed an important variability in the choice of 1) threshold values for 25(OH)D insufficiency or deficiency, 2) 25(OH)D measurement methods, and 3) trimester in which 25(OH)D concentrations were measured. Blood samples were taken once during pregnancy in a large majority of studies, which may not be representative of vitamin D status throughout pregnancy. Most studies reported adjustment for confounding factors including season of blood sampling, but very few studies used the 25(OH)D gold standard assay, the LC-MS/MS. Prospective studies assessing maternal 25(OH)D concentrations 1) by standardized and validated methods, 2) at various time points during pregnancy, and 3) after considering potential confounding factors, are needed.

Maternal risk factors and newborn infant vitamin D status: a scoping literature review

Low vitamin D (VitD) status is common among newborn infants, more so in temperate latitudes with evidence that maternal VitD deficiency is a major risk factor given that the neonate relies solely on maternal-fetal transfer of VitD. This scoping review was conducted to provide an overview of the latest evidence from studies regarding the impact of maternal risk factors on infant 25-hydryoxyvitamin D [25(OH)D] concentrations with a focus on studies in Canada and the United States. Several maternal risk factors that contribute to low maternal-fetal 25(OH)D concentrations have been reported over many decades, but no clear pattern has been established for multiethnic populations. For example, darker skin pigmentation and ethnicity are common risk factors for low VitD status. Studies in predominantly white women showed that supplementation of VitD during pregnancy causes significant increases in maternal serum 25(OH)D which often improves cord serum 25(OH)D values. In addition, VitD recommendations by health care professionals and adherence to supplementation by pregnant women appear to positively influence maternal and infant 25(OH)D concentrations. Conversely, winter season, obesity, lower socioeconomic status including lifestyle factors (smoking), and use of medication pose risk for lower maternal-fetal transfer of VitD. However, there is still a dearth of pertinent data on the relationship between some of the maternal risk factors and newborn 25(OH)D concentrations, for instance, relationships between gestational diabetes and neonatal VitD status. Additional research is required to determine if the same target for 25(OH)D concentrations applies for pregnant women, neonates, and infants.

The State of Knowledge about Nutrition Sources of Vitamin D, Its Role in the Human Body, and Necessity of Supplementation among Parents in Central Poland

The percentage of children with vitamin D deficiency in Poland is alarming. The aim of the study was to assess the knowledge about sources of food and the function of vitamin D, as well as the frequency of its supplementation. A survey was conducted among the parents of children from Central Poland attending primary schools, and a questionnaire containing mainly open-ended questions was used to collect the data. Most mothers knew at least one of the functions of vitamin D in the body but had a low level of knowledge about its dietary sources. Only a small group of respondents supplemented themselves and their children with vitamin D. Statistically significant influences on the level of knowledge about the functions and sources of vitamin D were place of residence (i.e., better knowledge in the countryside) and mothers’ level of education (i.e., the better educated, the greater knowledge). In the case of monthly income level, such impact was observed only in relation to the knowledge of vitamin D functions. Concerning the frequency of supplementation, only maternal level of education had a statistically significant effect (i.e., the higher the education level, the higher the frequency of supplementation). In addition, mothers who were aware of functions of vitamin D and nutritional sources, significantly more frequently supplemented vitamin D.

Vitamin D, Gestational Diabetes, and Measures of Glucose Metabolism in a Population-Based Multiethnic Cohort

OBJECTIVE

We explored associations between maternal 25-hydroxyvitamin D (25(OH)D) status during pregnancy and gestational diabetes (GDM) and other measures of glucose metabolism.

METHODS

We analysed 25(OH)D at 15 and 28 gestational weeks (GW) in 745 multiethnic pregnant women attending antenatal care units in Oslo, Norway, between 2008 and 2010. GDM was diagnosed with a 75 g oral glucose tolerance test at 28 GW. Separate regression analyses were performed to investigate associations between 25(OH)D and GDM and measures of glucose metabolism.

RESULTS

A higher proportion of ethnic minority women had GDM (p < 0.01) and low 25(OH)D (p < 0.01) compared to Europeans. In logistic regression analyses, 25(OH)D < 50 nmol/L was associated with GDM after adjusting for age, parity, education, and season (OR 1.6; 95% CI 1.1-2.2). After additional adjustments for variables reflecting fat mass (skinfolds or BMI) and ethnicity, the association disappeared with ethnicity having a much stronger effect than the adiposity variables. We got similar results exploring effects on other measures of glucose metabolism and when change in 25(OH)D from inclusion to 28 GW was taken into account.

CONCLUSIONS

Vitamin D deficiency was not associated with GDM or glucose metabolism in a multiethnic population-based study, after adjustments for confounding factors, in particular ethnicity.

Ethnic disparities in the dietary requirement for vitamin D during pregnancy: considerations for nutrition policy and research

Despite the inverse association between skin colour and efficiency of cutaneous vitamin D synthesis, in addition to the widely accepted racial disparity in vitamin D status, populations of ethnic minority are understudied in terms of setting target serum 25-hydroxyvitamin D concentrations and corresponding dietary requirements for vitamin D. In minority groups, prevention of vitamin D deficiency on a population basis is challenging due to the lack of clarity surrounding the metabolism and transport of vitamin D. Authoritative agencies have been unable to define pregnancy-specific dietary recommendations for vitamin D, owing to an absence of sufficient evidence to confirm whether nutritional requirements for vitamin D are altered during pregnancy. While the question of setting race- and pregnancy-specific dietary reference values for vitamin D has not been addressed to date, endemic vitamin D deficiency has been reported among gravidae worldwide, specifically among ethnic minorities and white women resident at high latitude. In light of the increased risk of nutritional rickets among infants of ethnic minority, coupled with growing evidence for potential non-skeletal roles of vitamin D in perinatal health, determination of the dietary vitamin D requirement that will prevent deficiency during pregnancy is a research priority. However, systematic approaches to establishing dietary requirements are limited by the quality of the available evidence and the under-representation of minority groups in clinical research. This review considers the evidence for racial differences in vitamin D status and response to vitamin D supplementation, with particular application to pregnancy-specific requirements among ethnic minorities resident at high latitudes.

Knowledge, awareness, attitudes and sources of vitamin D deficiency and sufficiency in Saudi children

OBJECTIVES

To examine the awareness, knowledge, and attitudes regarding vitamin D and its sources among Saudi Arabian children. 

METHODS

One hundred patients (vitamin D-deficient children) and 100 healthy children participated in the study. Participants were interviewed separately on topics including their awareness, knowledge, and attitudes regarding vitamin D using multiple-choice, and short-answer questions. This prospective, cross-sectional study was performed on children and adolescents between January 2011 and December 2011 at the Security Forces Hospital, Riyadh, Saudi Arabia. 

RESULTS

Only 28% were aware of the sources of vitamin D, while 64% of healthy subjects were aware. Similarly, only 50% of patients and their parents knew of the health benefits of vitamin D, while 70% of healthy subjects had knowledge. Hence, our findings agree with previous findings that low levels of awareness and knowledge regarding vitamin D and its sources persist.  

CONCLUSION

Most vitamin D deficient cases were unaware of vitamin D sources. However, half of the patient/parents were aware of benefits of vitamin D. Hence, we recommend that an improved campaign for awareness, knowledge, and attitudes regarding vitamin D and its sources are needed.

Psychometric Properties of a Developed Questionnaire to Assess Knowledge, Attitude and Practice Regarding Vitamin D (D-KAP-38)

The aim of this study was to develop a valid and reliable questionnaire to assess vitamin D-related knowledge, attitude and practices in Tehranian adults, who may be at increased risk of vitamin D deficiency. This study was conducted on 572 individuals, aged ≥20 years from public health care centers in Tehran, Iran. Based on results of a literature review and in-depth interviews, the 38-item vitamin D-related KAP questionnaire (D-KAP-38) with four subscales was developed: (1) general knowledge; (2) nutritional knowledge; (3) attitudes; (4) behaviors. Validity of the D-KAP-38 questionnaire was assessed, utilizing face, content, and construct validity methods. Internal consistency was calculated to assess reliability of the current developed questionnaire. A total of 572 (54.1% female) adults, aged 30.2 ± 7.9 years, participated in the study. All items were perceived as relevant and comprehendible by participants. Content validity was confirmed by a panel of experts. The internal consistency, as measured by Cronbach's alpha coefficients, exceeded the minimum reliability standard of 0.60 for four subscales. Exploratory factor analysis suggested a four-factor construct and the results of the confirmatory factor analysis indicated acceptable fit indices for the proposed model. No ceiling effects were observed except for general knowledge (1.2%). Floor effects detected were 0%, 1.1%, 2.4%, and 8.7% for practice, attitude, general knowledge, and nutrition knowledge, respectively. General knowledge had the highest score (79.59 ± 14.52) and nutrition knowledge had the lowest (42.58 ± 20.40), among the four sub-scales. Results confirm the initial validity and reliability of D-KAP-38 questionnaire. Further investigations in different populations are recommended.

Knowledge and attitudes about vitamin D, and behaviors related to vitamin D in adults with and without coronary heart disease in Saudi Arabia

Background

Vitamin D deficiency is prevailing in Saudi Arabia. Recent national data indicated an inverse association between vitamin D status and coronary heart disease (CHD), which increases concerns about vitamin D deficiency as a serious public health problem. Therefore, the current study aimed to investigate whether knowledge, attitudes and behaviors related to vitamin D contribute to the prevalence of vitamin D deficiency among adults with and without CHD in Saudi Arabia.

Methods

This case-control study consisted of 130 CHD cases and 195 matched controls. The study subjects were recruited from three hospitals in Saudi Arabia. Structured interviews were completed to collect data on participants’ socio-demographics, knowledge about vitamin D, attitudes toward sun exposure, and behaviors related to vitamin D. Also, serum vitamin D levels were measured.

Results

Severe vitamin D deficiency [serum 25(OH)D < 10 ng/mL] was more prevalent in the CHD cases than in the controls (46% and 3%, respectively). The total knowledge score was higher in the controls than in the cases [2.5 (±1.8) and 1.6 (±2.2), respectively]. The cases had better attitudes toward sun exposure compared to the controls (p = 0.001); however, the controls had better attitudes toward vitamin D compared to the cases (p = 0.001). The controls had a higher consumption of multivitamin supplements than the cases (6.7% and 0.8%, respectively; p = 0.010). Similarly, the controls had a higher consumption of butter (p = 0.001), oily fish (p = 0.004), and liver (p = 0.003) than the cases; however, the cases had a significantly higher intake of milk (p = 0.001). A multivariate logistic regression showed that vitamin D deficiency [25(OH)D < 20 ng/mL] was associated with low levels of knowledge about vitamin D, with an odds ratio of 1.82 (95% CI: 1.08–3.06, P = 0.024). Vitamin D deficiency was also associated with low intake of vitamin supplements, with an odds ratio of 4.35 (95% CI: 2.12–8.92, P < 0.001).

Conclusion

The present study revealed that low levels of knowledge about vitamin D and low consumption of vitamin supplementation, including vitamin D, calcium, multivitamin, and calcium supplements with vitamin D, may have contributed to the higher prevalence of vitamin D deficiency among the CHD cases than among the controls. Further studies using a qualitative approach are crucial to explore the underlying reasons for low knowledge about vitamin D and behaviors related to vitamin D including the intake of vitamin supplementation  that may contribute to the high burden of vitamin D deficiency in the country.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4183-1) contains supplementary material, which is available to authorized users.

Calcium intake in winter pregnancy attenuates impact of vitamin D inadequacy on urine NTX, a marker of bone resorption

PURPOSE

Pregnancy is characterised by increased bone turnover, but high bone turnover with resorption exceeding formation may lead to negative maternal bone remodelling. Recent studies are conflicting regarding the effect of calcium on skeletal health in pregnancy. The aim of this study was to examine the seasonal effect of serum 25-hydroxyvitamin D (25OHD) and dietary calcium on a marker of bone resorption.

METHODS

This was prospective study of 205 pregnant women [two cohorts; early pregnancy at 13 weeks (n = 96), and late pregnancy at 28 weeks (n = 109)]. Serum 25OHD and urine cross-linked N-telopeptides of type I collagen (uNTX) were measured at both time points. Intakes of vitamin D and calcium were recorded using 3-day food diaries at each trimester.

RESULTS

Compared to summer pregnancies, winter pregnancies had significantly lower 25OHD and significantly higher uNTX. Higher calcium intakes were negatively correlated with uNTX in winter, but not summer. In late pregnancy, compared to those reporting calcium intakes ≥1000 mg/day, intakes of <1000 mg/day were associated with a greater increase in uNTX in winter pregnancies than in summer (41.8 vs. 0.9%). Increasing calcium intake in winter by 200 mg/day predicted a 13.3% reduction in late pregnancy uNTX.

CONCLUSIONS

In late pregnancy, during winter months when 25OHD is inadequate, intakes of dietary calcium <1000 mg/day were associated with significantly increased bone resorption (uNTX). Additional dietary calcium is associated with reduced bone resorption in late pregnancy, with greater effect observed in winter. Further research regarding optimal dietary calcium and 25OHD in pregnancy is required, particularly for women gestating through winter.

Seasonal variation in Internet searches for vitamin D

Internet search rates for "vitamin D" were explored using Google Trends. Search rates increased from 2004 until 2010 and thereafter displayed a seasonal pattern peaking in late winter. This knowledge could help guide the timing of public health interventions aimed at managing vitamin D deficiency.

PURPOSE

The Internet is an important source of health information. Analysis of Internet search activity rates can provide information on disease epidemiology, health related behaviors and public interest. We explored Internet search rates for vitamin D to determine whether this reflects the increasing scientific interest in this topic.

METHODS

Google Trends is a publically available tool that provides data on Internet searches using Google. Search activity for the term "vitamin D" from 1st January 2004 until 31st October 2016 was obtained. Comparison was made to other bone and nutrition related terms.

RESULTS

Worldwide, searches for "vitamin D" increased from 2004 until 2010 and thereafter a statistically significant (p < 0.001) seasonal pattern with a peak in February and nadir in August was observed. This seasonal pattern was evident for searches originating from both the USA (peak in February) and Australia (peak in August); p < 0.001 for both. Searches for the terms "osteoporosis", "rickets", "back pain" or "folic acid" did not display the increase observed for vitamin D or evidence of seasonal variation.

CONCLUSION

Public interest in vitamin D, as assessed by Internet search activity, did increase from 2004 to 2010, likely reflecting the growing scientific interest, but now displays a seasonal pattern with peak interest during late winter. This information could be used to guide public health approaches to managing vitamin D deficiency.

What Do People Know and Believe about Vitamin D?

People have been exposed to a lot of information regarding vitamin D, with evidence suggesting that vitamin D may be involved in numerous health conditions, subsequently creating concerns about vitamin D insufficiency. As a result, what do people really know or believe about this topic? In this cross-sectional study, we assessed vitamin D-related knowledge and beliefs in 59,273 French adults (NutriNet-Santé cohort) using a specific questionnaire. Answers to this questionnaire were weighted according to the French sociodemographic distribution and compared across individual characteristics, using χ²-tests. Physicians and media were identified as key information providers. Participants did not always accurately cite vitamin D sources (e.g., 72% only for sun exposure, fatty fish: 61%) or established health effects (e.g., bone health: 62%–78%). Conversely, they mentioned incorrect sources and health effects for which there is no consensus yet (e.g., skin cancer). These findings were modulated by age/generational and socioeconomic factors. A strong inconsistency was also observed between participants’ true vitamin D status (plasma 25-hydroxyvitamin D concentration) and their opinion about it. This study, the first in Europe with such a large sample, stresses the need for simple and up-to-date supports of communication for the public and healthcare professionals regarding sources and health effects of vitamin D.

Vitamin D status and fertility outcomes during winter among couples undergoing in vitro fertilization/intracytoplasmic sperm injection

OBJECTIVE

To assess the vitamin D status of men and women undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI), and to investigate associations between vitamin D status and fertility variables.

METHODS

A cross-sectional prospective study was undertaken of men and women attending a fertility clinic in Ireland for IVF/ICSI between January and March 2014. Vitamin D status was determined by measurement of serum 25-hydroxyvitamin D (25(OH)D). Questionnaires examined knowledge and practices concerning vitamin D. Fertility variables and pregnancy outcomes were assessed in relation to vitamin D status.

RESULTS

Overall, 73 men and 64 women provided blood samples. Among men, no correlation was found between 25(OH)D and total motility (ρ=0.069, P=0.562), progressive motility (ρ=0.066, P=0.576), count (ρ=0.001, P=0.996), or morphology (ρ=-0.034, P=0.774) of sperm. Additionally, there was no association between 25(OH)D and ongoing pregnancy rates (P=0.158). There was no difference in 25(OH)D between men with and without male factor subfertility issues (P=0.856). Among women, there was no significant correlation between 25(OH)D and anti-Müllerian hormone (P=0.629) or number of collected (P=0.198) and fertilized oocytes (P=0.136). There was no difference in 25(OH)D between women with and without ongoing pregnancy (P=0.222).

CONCLUSION

No correlation was found between fertility variables or pregnancy outcomes and male or female vitamin D status.

Vitamin D deficiency and supplementation in pregnancy in a multiethnic population-based cohort

BACKGROUND

To investigate ethnic differences in vitamin D levels during pregnancy, assess risk factors for vitamin D deficiency and explore the effect of vitamin D supplementation in women with deficiency in early pregnancy.

METHODS

This is a population-based, multiethnic cohort study of pregnant women attending Child Health Clinics for antenatal care in Oslo, Norway. Serum-25-hydroxyvitamin D [25(OH)D] was measured in 748 pregnant women (59% ethnic minorities) at gestational weeks (GW) 15 (SD:3.6) and 28 (1.4). Women with 25(OH)D <37 nmol/L at GW 15 were for ethical reasons recommended vitamin D3 supplementation. Main outcome measure was 25(OH)D, and linear regression models were performed.

RESULTS

Severe deficiency (25(OH)D <25 nmol/L) was found at GW 15 in 45% of women from South Asia, 40% from the Middle East and 26% from Sub-Saharan Africa, compared to 2.5% in women from East Asia and 1.3% of women from Western Europe. Women from South Asia, the Middle East and Sub-Saharan Africa had mean values that were -28 (95 % CI:-33, -23), -24 (-29, -18) and -20 (-27, -13) nmol/L lower than in Western women, respectively. Ethnicity, education, season and intake of vitamin D were independently associated with 25(OH)D. At GW 28, the mean 25(OH)D had increased from 23 (SD:7.8) to 47 (27) nmol/L (p < 0.01) in women who were recommended vitamin D supplementation, with small or no change in women with sufficient vitamin D levels at baseline.

CONCLUSIONS

Vitamin D deficiency was prevalent among South Asian, Middle Eastern and African women. The serum levels of 25(OH)D increased significantly from GW 15 to 28 in vitamin D deficient women who received a recommendation for supplementation. This recommendation of vitamin D supplementation increased vitamin D levels in deficient women.

Maternal-fetal impact of vitamin D deficiency: a critical review

Research into the extra-skeletal functions of vitamin D has been expanding in recent years. During pregnancy, maternal vitamin D status may be of concern because of the key role of this vitamin in fetal skeletal development and due to the association between hypovitaminosis D and adverse maternal-fetal outcomes. Therefore, the objective of this manuscript was to review the maternal-fetal impact of gestational vitamin D deficiency and the benefits of vitamin D supplementation during pregnancy. A literature search was performed in PubMed and Embase employing the following keywords: vitamin D deficiency, pregnancy, 25-hydroxyvitamin D, and hypovitaminosis D. All relevant articles in English language published since 1980 were analysed by the two authors. Neonatal complications derived from vitamin D deficiency include low birth weight, growth restriction, and respiratory tract infection. In the mother, vitamin D deficiency has been associated with altered glucose homeostasis and increased incidence of gestational diabetes mellitus, pre-eclampsia, and bacterial vaginosis. However, the current state of the evidence is controversial for some other endpoints and the actual benefit of vitamin D supplementation in pregnancy remains unclear. Additional longitudinal studies may clarify the actual impact of vitamin D deficiency during pregnancy, and randomised trials are required to define the benefits of vitamin D supplementation in reducing the incidence of adverse outcomes in the mother and infant.

Knowledge and attitudes to vitamin D and sun exposure in elite New Zealand athletes: a cross-sectional study

Background

Sun safety and vitamin D status are important for prolonged health. They are of particular interest to those working with athletes for whom for whom safe sun practices maybe limited.

The aim of this cross-sectional study was to describe the attitudes of elite New Zealand athletes to both vitamin D and sun exposure.

Methods

110 elite New Zealand outdoor athletes volunteered to participate in an interview with a trained interviewer. The interviewer asked the athletes questions on their Vitamin D knowledge, attitudes and practices regarding sun exposure as well as their concerns about skin cancer.

Results

Athletes were more concerned about their risk of skin cancer (66%) than their vitamin D status (6%). Although the majority (97%) were aware of Vitamin D and could identify the sun as a source (76%) only 17% could name another source of Vitamin D.

Only 10 (9%) reported always applying sunscreen before going out in the sun. No athlete reported reapplying sunscreen every hour and 25 suggesting that they never reapply sunscreen.

Conclusions

Athletes are concerned about skin cancer however, their use of sunscreen is not optimal suggesting reapplication of sunscreen could be targeted in order to reduce the risk of sun cancer. Awareness of sources of Vitamin D other than the sun may also need to be improved potentially through educational interventions and possibly in conjunction with sun smart messages.

Pregnant immigrant Nigerian women: an exploration of dietary intakes

OBJECTIVE

The aim of the study is to explore the dietary intakes of a prominent ethnic minority group of women from Sub-Saharan Africa during pregnancy, in order to identify nutritional issues of concern which may impact on pregnancy outcomes and whether different food based dietary guidelines may be required to meet their needs.

STUDY DESIGN

This is an observational study with quantitative assessment of nutrient intakes and an exploration of meal composition and food choices.

METHODS

Fifty-two Nigerian pregnant women in their second or third trimester of pregnancy were recruited from antenatal clinics in the National Maternity Hospital, Dublin, Ireland. Early pregnancy weight was measured and body mass index recorded. A 24 h dietary recall was used to assess food and nutrient intakes.

RESULTS

Eighty-nine per cent of the study population were classified as overweight or obese. These women appear to be maintaining traditional African dietary habits and have a healthy macronutrient composition in the diet. The intake of key pregnancy micronutrients such as calcium, vitamin D and folate may be insufficient from diet alone to meet requirements and supplements may be inadequately utilized in a timely manner.

CONCLUSIONS

These women represent a vulnerable obstetric group that may be at risk of adverse pregnancy outcomes due to high obesity rates and inadequate micronutrient status in early pregnancy. Provision of dietary advice should be tailored to suit their cultural dietary practices and food preferences. Pre-conception counselling on healthy lifestyle and appropriate supplement usage may be beneficial, although larger studies are required to assess the need for specific nutrition policy recommendations.

Human cathelicidin production by the cervix

hCAP18/LL-37 is the sole human cathelicidin; a family of host defence peptides with key roles in innate host defence. hCAP18/LL-37 is expressed primarily by neutrophils and epithelial cells, but its production and function in the lower genital tract is largely uncharacterised. Despite the significant roles for cathelicidin in multiple organs and inflammatory processes, its impact on infections that could compromise fertility and pregnancy is unknown. The aim of this study was to investigate cathelicidin production, regulation and function in the cervix. hCAP18/LL-37 was found to be present in cervicovaginal secretions collected from women in the first trimester of pregnancy and to be expressed at significantly higher levels in samples from women with alterations in vaginal bacterial flora characteristic of bacterial vaginosis. In endocervical epithelial cell lines, expression of the gene encoding hCAP18/LL-37 (CAMP) was not affected by TLR agonists, but was found to be up-regulated by both 1, 25 hydroxyvitamin D₃ and 25 hydroxyvitamin D₃. However, no association was found between serum levels of vitamin D and hCAP18/LL-37 concentrations in cervicovaginal secretions (n = 116). Exposure to synthetic LL-37 had a pro-inflammatory effect on endocervical epithelial cell lines, increasing secretion of inflammatory cytokine IL-8. Together these data demonstrate inducible expression of hCAP18/LL-37 in the female lower reproductive tract in vivo and suggest the capacity for this peptide to modulate host defence to infection in this system. Further investigation will elucidate the effects of hCAP18/LL-37 on the physiology and pathophysiology of labour, and may lead to strategies for the prevention of infection-associated preterm birth.

The double-edged sword of vitamin D in Ireland: the need for public health awareness about too much as well as too little

INTRODUCTION

The Institute of Medicine (IOM) 2011 on dietary references intakes for calcium and vitamin D specified that a 25-hydroxyvitamin D (25OHD) level below 30 nmol/L indicated risk of deficiency and that a level above 125 nmol/L indicated risk of harm.

METHODS

We noted a high prevalence of hypovitaminosis D (23.9 %) and a substantive prevalence of hypervitaminosis D (4.8 %) in a retrospective audit of clinical samples (n = 10,181) obtained over 10 months in 2013.

CONCLUSION

Hypovitaminosis D should be corrected by low dose supplementation (5 µg or 200 IU daily) with some at-risk groups needing higher doses (10 µg or 400 IU daily) based on 25OHD levels. Whereas, those taking high-dose vitamin D supplements based on mistaken beliefs about recently authorised claims of benefit for muscle function and misleading unauthorised claims need to be alerted to the potential harms of excessive supplementation.