Although Jordan is considered a sunny country, 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.
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 significantly 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 benefits, and causes of its deficiency
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 benefit, 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 deficiency (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 identified oily fish 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 deficiency and its related factors.
The escalating problem of vitamin D deficiency in the region was perceived by more than two-thirds of participants, with females being significantly 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 insufficiency was reported by (40%) of the participants as a possible cause of vitamin D deficiency, no significant 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 deficiency 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 insufficient sun exposure and vitamin D deficiency was observed among the participants. This was not observed in a Pakistani (29) study where only 36% of participants identified exposure to sunlight as a factor influencing 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 filters 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 significantly 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 significantly more sun exposure at that time than those who were unaware of this fact. Therefore, a more detailed message defining 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 significantly 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 deficiency in real-life setting(35) and this was found in the current study, as four-fifths of the participants felt that sunscreen usage would not lead to vitamin D deficiency.
Knowledge attitudes, and practice, toward vitamin D supplementation
Despite the high prevalence of vitamin D deficiency and insufficiency 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 significantly contributed to the vitamin D supplements use was the consumption of vitamin D fortified food, unlike other studies, that reported knowledge scores had the greatest influence (17,21).
It is worth reporting that milk was the second most consumed food among the participants, therefore milk fortification may help solve the vitamin D deficiency problem in Jordan as one glass containing about four cubic centimeters of fortified 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 deficiency like skin color and cultural expectations of clothing are impossible or hard to modify. Therefore, more emphasis should be place on important alternative modifiable factors including use of vitamin D supplement and food fortification, which might improve the low vitamin D status.
Strengths and limitations
First, this study is the first 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: first, 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.