Students’ ”D”ILEMMA: An Assessment of Knowledge, Attitudes and Practice Toward Vitamin D Among University Students

Background: The message delivered to the public regarding vitamin D is unclear, and contradictory; particularly regarding sun exposure; previous studies in Jordan have revealed high prevalence of low vitamin D among university students. The aim of this study was to investigate university students’ knowledge, attitudes and practice regarding vitamin D. Method: A web-based cross-sectional survey completed by students at a Jordanian university in 2019. Binary logistic regression analysis was used to predict supplement use. Results: 496 students completed the questionnaire. The mean knowledge score was 31.3 (± 11.3) out of 100. Women had signicantly higher beliefs that vitamin D deciency is an escalating health issue (p<0.01). Negative practices regarding sun exposure was signicantly higher in women than men (p<0.01). The majority of participants recognized that insucient sun exposure was a cause of vitamin D deciency, but 50.7 % avoid sun exposure, and 67.6% expose only their face and hands. The consumption of fortied foods (OR 3.59-;p<0.001) was the only studied variable associated with vitamin D consumption. Conclusion: There is a gap between knowledge, attitude, and practice regarding vitamin D which can be bridged by promoting Vitamin D related awareness.

Physical activity was assessed by asking the students how many times per week they exercise enough to work up a sweat. Students were classi ed as physically active if they exercise to a sweat three or more times per week. Exposure to the sun at home was classi ed into four categories: no exposure, sun exposure via window glass only, has an open area for sun exposure with lack of privacy, and place of residence has an open area for sun exposure with high privacy.
As there is no local validated questionnaire for assessment of dietary vitamin D intake, vitamin D containing food items were obtained from a short validated questionnaire (15) and the frequencies of intake were measured according to a Jordanian validated food frequency questionnaire (16). The nal version of the questionnaire includes four food items: oily sh, butter, egg, and meat, in addition to low vitamin D sources including olive oil and unforti ed milk.
Knowledge, attitude, and practice To assess knowledge we developed a questionnaire consisting of 30 questions. Knowledge score was calculated according Boland et al. (17) (See Additional le 1). One point was added for each correct answer in questions that included one correct option, and for questions with multiple correct answers, one point was counted for each correct choice and one point was subtracted for each incorrect choice. The scores then were converted to percentages by dividing the scores by the highest possible score (30), then multiplied by 100. Regarding the question on the best time to be exposed to the sun to induce vitamin D synthesis, participants were provided with 5 answers; any student who answered one or more correct answer without choosing any incorrect answer was categorized as knowledgeable about the best time to be exposed to the sun.. Additional questions that evaluated attitudes and practices about vitamin D and sun exposure were included in the questionnaire. To assess the consumption of vitamin D rich food, points were added based on the consumption frequencies (less than once weekly: 1 point, once weekly: 2 points, and more than once weekly: 3 points). Frequencies were transformed into percentages.
Validation of the questionnaire The questionnaire content validity was evaluated by and expert panel composed of three experts. Formulated in English the questionnaire was translated to Arabic and back translated by different translator, then the two English version were compared. Face validity of the Arabic version was conducted by interviewing 30 students and the questionnaire was modi ed according to their feedback. The responses from the pilot testing were excluded from the nal analysis.

Statistical Analysis
Descriptive statistics were used to describe the study ndings. Categorical variables were presented as frequencies (percentages) whereas continuous variables were presented as means (standard deviations). The χ2 test was used to assess the associations between the sample characteristics and their vitamin D knowledge and practices and to evaluate the association between participants' knowledge and practices. Binary logistical regression was conducted to assess the contribution of different factors to the use of vitamin D supplements and the results of the regression were represented as odds ratios and 95% Con dent Interval (CI). P-values <0.05 were considered signi cant. IBM SPSS Statistics 25 was used to analyze the data and to create gures.

Results
The number of sent invitations was 2,150 (the number of eligible students who were registered in the summer semester). We received responses from 496.
The response rate was 23%), which is higher than the minimum acceptable response rate(18).

Socio-demographic characteristics
The socio-demographic characteristics of participants are shown in Table 1. Females made up 67.1% of the participants . The mean age of the participants was 23.52 ± 4.1 years. The skin color of most of the participants ranged between Fitzpatrick skin type III (light brown) (41.1%) and type IV (moderate brown) (43.1%). Almost three-quarters of participants (74.6%) of the participants were physically inactive.
The largest group of the participants (46%) had access to an open area in their homes but without privacy, and only 2.8% reported that they had no kind of sun exposure in their home.
Sources of information about vitamin D and attitude toward vitamin D As Table 2 shows, all participants had heard of vitamin D and the majority of the participants (78.8%) indicated that the primary source of information about vitamin D was from educational centers, followed by healthcare providers (42.9%). Likewise, the preferred source of information for more than half of them (53%) was educational centers followed by healthcare providers (38.5%). Most (79.4%) participants agreed that vitamin D de ciency is an escalating health issue in the region and all were interested in getting more knowledge about vitamin D. Nevertheless, 44.6% of participant were unconcerned about their vitamin D levels.
Knowledge and attitudes regarding vitamin D health bene ts and the causes of its de ciency Most participants knew that vitamin D is essential for bone integrity and for prevention of osteoporosis, but none knew that there is a role of vitamin D in prevention of osteomalacia (Table 2). Moreover, other essential bene ts of vitamin D were less known; only a third (32.5%) of participants knew that vitamin D is important for the integrity of muscles. The primary cause of vitamin D de ciency according to participants was insu cient sun exposure (82.3%), followed by insu cient nutritional intake (39.7%) and the least mentioned cause was obesity (10.7%).
Knowledge and attitude regarding nutritional sources of vitamin and sun exposure As shown in Table 2, 52.8% of participants acknowledged that the nutritional sources of vitamin D are insu cient and most of them (75.8%) believed that the main source of vitamin D is the sun. Nevertheless, 75.6% did not know the best time to be exposed to the sun for cutaneous production of vitamin D and 36.3% of the participants were aware of the association between dark skin color and vitamin D de ciency. Only 9.7% of the participants regarded oily sh as a source of vitamin D. The majority 78.6%) of respondents believed that vitamin D consumption is important only when sun exposure is limited and 79.4% believed that vitamin D rich foods are costly.
Participants' knowledge scores are presented as percentages ( Figure 1). The mean (±SD) was 31.3% (± 11.25) and only 7% of the participants got a score of 50% and above. The highest score was 66.67%.

Sun exposure practice
As Table 3 shows 50.6% of the participants usually avoid exposure to the sun, and 57.9% routinely use sunscreen. From 10 am to 4 pm, 45.6% spend only less than 30 minutes outdoors during the weekdays and 62.3% of them spend less than 30 minutes outdoors during the weekends. Moreover, only 26.6% were exposed to the sun in the right time for vitamin D synthesis. The main sun-exposed body parts of the participants were face and hands (67.7%), legs were exposed in 6.7% of the participants. Totally covered body with no parts exposed to the sun was practiced by (2.2%) of the participants.
Vitamin D containing food, forti ed food and vitamin D supplement, consumption practice As indicated by the weekly frequency of vitamin D rich food consumption (Table 3), the least consumed food was oily sh, followed by butter, eggs. The most consumed was meat. A third of participants reported that they are taking vitamin D supplements. Regarding the consumption of vitamin D-forti ed food, 34.5% of the participants reported consuming forti ed food and 48.8% were unsure. Figure 2 shows the consumption of vitamin D rich food percentages, the mean was 72.9% (± 14.7). Over 95% of participants got a score of 50% or more and the lowest reported percentage was 33.3%.
Association between sample characteristics and knowledge and practices related to vitamin D Table 4 shows that females signi cantly higher beliefs that vitamin D de ciency is an escalating health issue (84.7%) than males. In addition, their negative practices regarding sun exposure was statistically signi cant compared to males, as they reported covering more of their bodies, exposing only face and hands (81.1%) and spend less than 30 minutes during 10 am-4pm time period of the day outside during weekends (64.6%) . Signi cant differences between male and females, were found in use of sunscreen and avoidance of sun exposure habits -only (6.7%) of males used sunscreen routinely compared to 82.9% of females, and 58% of females compared to 35.3% of males reported avoiding sun exposure.
Regarding the knowledge about the best time to be exposed to the sun for vitamin D synthesis (around the solar noon), 78.1% of females did not know the best time for vitamin D synthesis, which was re ected in their practice toward sun exposure as three-quarters of them (76%) reported being exposed to the sun during the time of day when little vitamin D synthesis might occur.

Association between vitamin D knowledge and beliefs with practices
As shown in Table 5, the participants who knew the best time for sun exposure for vitamin D synthesis had signi cantly higher sun exposure at the right time when compared with those who did not know (p<0.01). However, the beliefs of the sun as the best source of vitamin D, and insu cient sun exposure are the main cause of vitamin D de ciency did not have any signi cant effect on sun exposure time or duration of sun exposure during both weekdays and weekends. No signi cant association was found between the acknowledgment of a certain types of foods as a good source of vitamin D and their consumption. Table 6 shows the results of the logistical regression of the factors that can contribute to vitamin D supplement use. The only signi cant contribution was found for the consumption of forti ed foods which increased the odds of consuming vitamin D supplements.

Discussion
Although Jordan is considered a sunny country [2], the prevalence of low vitamin D status is high in both genders, particularly among young adults of (18-39 years) compared to older age groups (2,19).. This study aimed to evaluate the current knowledge, attitude, and practice towards vitamin D among young, educated, adults.

Knowledge score
The mean of knowledge score of the participants in this study was 31.3%, which is close to previously reported scores in China (20) and Canada(21) but signi cantly lower than that of undergraduate health science students in Saudi Arabia (22).
Overall, participants demonstrated that the term, "vitamin D" had been heard, which is higher than an Australian study in which more than one-third of the participants had not heard of vitamin D(23), although the latter group were not university students as in the current study.
Vitamin D -knowledge attitude and practice, regarding information sources, food sources, health bene ts, and causes of its de ciency Educational centers (schools and universities) were the most commonly reported and preferred source of information about vitamin D among the participants, followed by healthcare providers unlike other studies which found that healthcare providers(24) and the Internet (17) were the main knowledge sources for participants. Therefore, healthcare providers must develop their role, since they were the second most preferred source of information for the current study participants.
The essential role of vitamin D in bone integrity was the most recognized bene t, in line with a similar study conducted in the United Kingdom (17). The importance of vitamin D in maintaining normal calcium levels, and its role in muscle integrity were known by only half of participants. None of the participants knew of the role of vitamin D in the prevention of osteomalacia ,which is an early sign of vitamin D de ciency (25). However, this could be due to the lack of a clear diagnostic criteria of osteomalacia (25), or unfamiliarity of the term, that may lead to the ambiguity of the term among the general population. Furthermore, less than 10% of participants identi ed oily sh as a source of vitamin D and low percentages were also reported for other nutritional sources. This indicates that the main nutritional sources of vitamin D and their essential role in health were not well-known by those surveyed, which suggests an unmet educational need regarding vitamin D de ciency and its related factors.
The escalating problem of vitamin D de ciency in the region was perceived by more than two-thirds of participants, with females being signi cantly more aware of this issue, which is in line with previous a study (26). This emphasizes the need for better health education campaigns related to vitamin D that targets both males and females, especially because a previous Jordanian study indicated that the prevalence of low vitamin D status among males was low (54%)(3).
While nutritional insu ciency was reported by (40%) of the participants as a possible cause of vitamin D de ciency, no signi cant associations were found between participants' consumption of different vitamin D rich foods and their beliefs. However, their reported consumption of vitamin D rich food was better than the reported rates in a Sudanese study (27) which might contribute to the lower prevalence of vitamin D de ciency among Jordanian women than Sudanese women (28).
Knowledge, attitude and practice regarding the importance of sun exposure for vitamin D synthesis High awareness of the relationship between insu cient sun exposure and vitamin D de ciency was observed among the participants. This was not observed in a Pakistani (29) study where only 36% of participants identi ed exposure to sunlight as a factor in uencing vitamin D production. Nevertheless, consistent with a Chinese study (20), the high level of awareness in Jordanian participants did not improve their sun exposure practice. The relationship between attitude and practice of sun exposure reported among the participants is non-linear. This non-linear relationship could be better understood if the state of sun exposure at the participants' home is investigated.
Clearly, there is a barrier for sun exposure among the participants as most did not have a private area for sun exposure at home. This means that participants, especially females, may be less comfortable exposing their body to the sun due to Jordanian cultural barriers. Consequently, the lack of privacy for sun exposure compelled a quarter of the participants to practice sun exposure via glass windows only, which lters out the UVB radiation required for vitamin D synthesis (30).
Moreover, many of the females in our study did not report exposure to the sun during right time for vitamin D synthesis (31). In addition, compared to males, females during weekends had signi cantly lower duration (< 30 min) of sun exposure during the period from 10 am to 4 pm, in which effective vitamin D production could be achieved.
It is noteworthy to mention that the participants, who were well-informed about the right time for sun exposure for vitamin D synthesis, practiced signi cantly more sun exposure at that time than those who were unaware of this fact. Therefore, a more detailed message de ning the correct time for sun exposure might enhance public sun exposure practice.
Furthermore, as reported in the present study, most of females in the conservative Jordanian society, cover most of their body parts sparing only their faces and hands, while the sun exposure of some of other body parts (eg back and legs)(1) is important for vitamin D synthesis. Similarly, males' exposure to sunlight did not differ much from the females' as 40.2% of the males exposed face/hands only.
Skin color has an important effect on the sun-induced synthesis of vitamin D, as the darker the skin, the less vitamin D is synthesized by sun exposure (32). In our study, participants' knowledge of this information was poor, which implies that there is a need to clarify the importance of skin color for vitamin D synthesis, especially among those with darker skin. Use of sunscreen was signi cantly higher in females than males, something also reported by an Indian study(33). Although in India this may be due to cultural factors related to skin colour with greater value placed on lighter skin tones(34). It is now generally accepted that sunscreen usage is not associated with vitamin D de ciency in real-life setting(35) and this was found in the current study, as four-fths of the participants felt that sunscreen usage would not lead to vitamin D de ciency.
Knowledge attitudes, and practice, toward vitamin D supplementation Despite the high prevalence of vitamin D de ciency and insu ciency among the Jordanian population(3), 60.5% of the participants did not consume vitamin D supplements, despite these being one of the main sources of vitamin D . The results of the logistical regression showed that the only studied factor that signi cantly contributed to the vitamin D supplements use was the consumption of vitamin D forti ed food, unlike other studies, that reported knowledge scores had the greatest in uence (17,21).
It is worth reporting that milk was the second most consumed food among the participants, therefore milk forti cation may help solve the vitamin D de ciency problem in Jordan as one glass containing about four cubic centimeters of forti ed milk will contain about 100 IU of vitamin D which counts for 1/6 of the daily recommended intake (600 IU/day) of vitamin D for those between 1-70 years of age(36).
Many factors that may predispose to vitamin D de ciency like skin color and cultural expectations of clothing are impossible or hard to modify. Therefore, more emphasis should be place on important alternative modi able factors including use of vitamin D supplement and food forti cation, which might improve the low vitamin D status.

Strengths and limitations
First, this study is the rst that evaluate knowledge, attitude, and practice toward vitamin D, among university students and in Jordanian population in general. Second, the sample size is larger than similar studies (17,37). Lastly, the study was conducted online, in a university with an infrastructure that allows free internet access for all students, where emails were sent to all of them, which eliminates coverage error, which led to a good response rate. However, there are several potential limitations of this study: rst, the questionnaire based on self-reporting, which could lead to recall bias. Second, our results are limited in generalizability as the study population consisted mainly of Jordanian students .. This educated population are likely to have led to an underestimation of the knowledge related to vitamin D in the wider Jordanian population. Third, a selection bias may have occurred, as the participation in this study is voluntary, those who participated in the study might had more interest in it than those who did not participate. Nevertheless, since the researchers have no knowledge regarding the views and the characteristics of those who choose not to respond, the reason for non-response cannot be accurately predicted.

Conclusion
A gap between participants' knowledge, attitudes and practices regarding vitamin D was observed. This gap which could be bridged through health policy makers adopting food-based strategies, and design effective campaigns to raise awareness of vitamin D, the importance of safe exposure to the sun expressed in unit of time, the use of vitamin D supplements, food forti cation and the regular inclusion of oily sh such as salmon in their diet to improve vitamin D status among the Jordanian population. Our results, might give a hint for the explanation of the high prevalence of low vitamin D among younger adults in the sunny Jordan. While this conclusion may not be generalizable to the whole population as our sample were drawn from a single university, our study provides a baseline for further quantitative and qualitative studies regarding vitamin D knowledge, attitudes and practices within the wider population.
Future studies could fruitfully explore this issue further by including vitamin D status as a proxy for vitamin D knowledge attitude and practice.

Declarations
Ethics approval and consent to participate An informed consent form included in the online questionnaire was completed by the participants. Ethical approval was obtained from ZUJ ethical committee before the commencement of the study. All methods were carried out in accordance with Declaration of Helsinki.

Consent for publication
Not applicable

Availability of data and materials
The datasets generated and/or analyzed during the current study are available in the Zenodo repository. https://doi.org/10.5281/zenodo.4261766 (38)

Competing interests
The authors declare that they have no competing interests.

Funding
This research was funded by ZUJ (for publishing fees).

Authors' contributions
NM and WQ made a substantial contribution to the design of the work, acquisition, analysis, and interpretation of data. MH and FE have drafted the work and substantially revised it. EG made a substantial contribution to the conception, designing of the work, and drafting it. JL helped with the interpretation of the data and the drafting of the manuscript. All authors reviewed the manuscript.