Vitamin D deficiency is prevalent across all age groups in epidemic proportions. The purpose of this study was to acquire a baseline assessment and create awareness among medical students regarding vitamin D. A cross-sectional, voluntary survey was conducted among undergraduate medical students. Data were collected using a questionnaire which assessed the level of knowledge students had with regard to where vitamin D comes from, what it does for health, how much is recommended, factors that affect its levels, and deficiency management. Majority of students were unaware that vitamin D deficiency has attained epidemic proportions. Though bone and skeletal disorders as a complication of vitamin D deficiency were known, a large number were unaware of systemic consequences (diabetes mellitus, cardiovascular diseases, and cancers). Only one-third of respondents were aware of duration and timing of sun exposure required for adequate serum vitamin D levels. However, we observed lack of awareness among students regarding the various biochemical forms, dose, and duration of vitamin D supplementation for treatment of nutritional deficiency. Our study highlighted a lack of knowledge about the importance of vitamin D, worldwide prevalence of vitamin D deficiency, and its management among medical students. Promoting vitamin D health awareness, if replicated across populations, could lead to positive health outcomes globally.
Vitamin D deficiency is a worldwide epidemic and yet, it is a problem that is largely unknown by majority of population [
One of the major reasons for the worldwide spread of this nutritional disorder has been lack of awareness about the importance of vitamin D, its health benefits, and prevention of deficient states across populations [
Our study was conducted among the MBBS undergraduate students about one and half year after enrolment in medical school, at the Department of Pharmacology, Vardhman Mahavir Medical College (VMMC) and associated Safdarjung Hospital, New Delhi, India. This research was conducted as a cross-sectional, voluntary survey over a period of one and a half year. The study was approved by the Institutional Ethics Committee of Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India.
The questionnaire was given to 300 undergraduate medical students. Before filling the questionnaire, necessary information was given by the researchers. The participants were allowed to get their doubts cleared. Data were collected using a questionnaire composed of two parts. First part included questions on age and gender and second half focused on vitamin D. The main objective of the study was to assess vitamin D knowledge among medical students. The 16-question, predominantly multiple-choice survey took approximately 15 minutes or less to complete. The survey questions assessed the level of knowledge students had with regard to where vitamin D comes from, what it does for health, how much is recommended, factors that affect vitamin D levels, and the prevalence of vitamin D deficiency. In our study, apart from questions on vitamin D deficiency and its management, two questions focused on sun exposure (duration and timing) in New Delhi, India, wherein the study was conducted (Table
Vitamin D: percentage of student’s response awareness of vitamin D.
Question |
|
---|---|
Status of vitamin D deficiency in India | |
Only in high risk groups | 60 (23.8) |
Urban population | 119 (47.2) |
Epidemic proportions | 45 (17.8) |
Rare | 21 (8.3) |
High risk groups for vitamin D deficiency | |
Infants, pregnant, and lactating women | 192 (76.1) |
Elderly | 15 (5.9) |
Patients with diabetes mellitus | 6 (2.3) |
People with naturally fair skin | 23 (9.1) |
None of the above | 16 (6.3) |
Problems associated with vitamin D deficiency | |
Bone and skeletal disorders | 238 (94.4) |
Diabetes mellitus | 2 (0.7) |
Cardiovascular disease | 1 (0.3) |
Cancer | 1 (1.1) |
Autoimmune disorders | 4 (1.5) |
None of the above | 2 (0.7) |
Sources of vitamin D | |
Green leafy vegetables | 43 (17.0) |
Sunlight that passed through glass | 83 (48.0) |
Milk | 57 (22.6) |
Egg yolk | 21 (8.3) |
None of the above | 10 (3.9) |
Adequate sun exposure to achieve sufficient vitamin D levels in New Delhi | |
Sun exposure (10 am–2 pm) on exposed arms and legs | 107 (42.4) |
Sunlight passed through glass (10 am–2 pm) on exposed arms and legs | 46 (18.2) |
Sunlight exposure through glass (2–4 pm) on exposed arms and legs | 9 (3.5) |
Sun exposure (7 am–10 am) on exposed arms and legs | 79 (31.3) |
None of the above | 11 (4.3) |
Minimum amount of sun exposure required for synthesis of vitamin D in New Delhi | |
1 hour/day | 87 (34.5) |
30 min/twice a week | 81 (32.1) |
2 hours a day | 51 (20.2) |
4 hour/twice a week | 24 (8.7) |
None of the above | 11 (4.3) |
RDA of vitamin D | |
600 IU | 62 (24.6) |
800 IU | 84 (33.3) |
1000 IU | 55 (21.8) |
2000 IU | 13 (5.1) |
Ever taken vitamin D supplement | |
No | 58 (23) |
Yes, with estimation of serum 25-hydroxyvitamin D levels | 61 (24.2) |
Yes, without estimation of serum 25-hydroxyvitamin D levels | 132 (52.3) |
Recommended form of vitamin D supplement for nutritional deficiency | |
Alfacalcidol | 19 (7.5) |
Cholecalciferol | 101 (40.0) |
Calcitriol | 105 (41.6) |
Either of the above | 22 (8.7) |
None of the above | 5 (1.9) |
Active biochemical form of vitamin D | |
Alfacalcidol | 2 (0.7) |
Calcitriol | 133 (52) |
Cholecalciferol | 99 (39.2) |
Ergocalciferol | 7 (2.7) |
None of the above | 18 (7.1) |
Vitamin D serum levels in an adult indicate | |
Insufficiency at 20–29 ng/mL; deficiency ≤20 ng/mL | 46 (18) |
Insufficiency at 10–19 ng/mL; deficiency ≤15 ng/mL | 50 (19.8) |
Insufficiency at 20–29 ng/mL; deficiency at ≤30 ng/mL | 56 (22.2) |
Insufficiency at 20–29 ng/mL; deficiency at ≤10 ng/mL | 35 (13.8) |
None of the above | 65 (25.7) |
Dose regime of vitamin D3 recommended for treatment of vitamin D deficiency | |
50,000 IU of vitamin D3 once a week for 6–8 weeks | 69 (27.3) |
60,000 IU once a week for 8 weeks | 29 (11.5) |
5000 IU once a week for 10 weeks | 86 (34.1) |
8000 IU/day for 6 months | 22 (8.7) |
None of the above | 46 (18.2) |
Biochemical form of vitamin D most commonly associated with hypercalcemia and hypervitaminosis | |
Calcitriol | 84 (33.3) |
Alfacalcidol | 37 (14.6) |
Cholecalciferol | 105 (41.6) |
None of the above | 37 (14.6) |
Are calcium supplements required for all in treatment of vitamin D deficiency | |
Yes | 164 (65) |
No | 88 (34.9) |
Validation of questionnaire to assess reproducibility and suitability was assessed using a small pretest in 10 subjects. The pretest participants were then contacted for their feedback and understanding with respect to the questionnaire. The Cronbach alpha was estimated to be 0.7, suggesting good internal consistency and an overall reliability. All student data were collected anonymously and deidentified by a member of staff not involved in the assessment of this cohort. After completion of the questionnaire, the students were taught about vitamin D, its importance, vitamin D deficiency, and its management in a lecture to create knowledge base.
Statistical analysis was carried out using SPSS. Descriptive statistics were used to characterize the population and to identify the frequencies of participant’s knowledge of vitamin D deficiency. A
Only 17.8% of participants correctly identified that vitamin D deficiency has achieved epidemic proportions, while less than half of the students believed that it is prevalent only in urban population (47.2%) or limited to high-risk groups (23.8%). Majority of the participants (76.1%) correctly identified infants, pregnant, and lactating women as high-risk groups. However, they were not aware (92%) that elderly and diabetics were also at a greater risk to develop vitamin D deficiency than the general population. Though bone and skeletal disorders as a complication of deficiency were known (94.4%), majority were unaware of the other systemic consequences (diabetes mellitus, cardiovascular diseases, and cancers) (Table
Approximately 48% of participants incorrectly identified that sunlight that passed through glass is a source of vitamin D. Milk/dairy products (22.6%) and eggs (8.33%) were recognised as vitamin D rich foods by few students. Although many were able to identify at least one correct source (30.9%), 17% of respondents also believed that green leafy vegetables are rich in vitamin D. Adequate sunlight exposure (10 am to 2 pm with arms and leg exposed), an important source of vitamin D, was recognised by 42.4% of participants. As for adequate duration of sun exposure required for vitamin D synthesis in Indian population, only one-third (32%) of respondents were aware of it.
About a quarter of our study population (24.6%) was aware of the recommended daily allowance (RDA) of vitamin D (600 IU) for adult men and women. Among the undergraduate students, majority (77%) had taken vitamin D supplements at some point of their life, though only few of them (24.2%) had been diagnosed with vitamin D deficiency (estimation of serum 25-hydroxyvitamin D levels) before administration.
About half of the participants (52%) correctly identified calcitriol as the active form of vitamin D for biochemical functioning in the body. Cholecalciferol was thought to be the active vitamin D by 39.2% participants. More than 80% of the students were unaware of the serum levels of vitamin D indicating insufficiency/deficiency that mandates treatment. With regard to the recommended forms of vitamin D for treatment of vitamin D deficiency, a similar number of participants identified cholecalciferol (40%) and calcitriol (41.6%). Only a quarter (27.3%) of students selected correct dosage regimen (50000 IU once a week for 6–8 weeks). Many students incorrectly associated cholecalciferol (41.6%) with hypercalcemia. Also, 34.9% of the participants were aware that calcium supplementation is important in treatment of vitamin D deficiency in cases of low dietary intakes of calcium.
The present study demonstrates gaps in basic knowledge about vitamin D, its benefits, and management of vitamin D deficiency among medical undergraduate students. Majority of the students believed that vitamin D deficiency is prevalent only in high-risk groups confined to urban areas. They were unaware that vitamin D deficiency has attained epidemic proportions across the world irrespective of age groups, populations, and geographical regions [
With regard to the importance of vitamin D, it is a key factor for maintenance of calcium and phosphate metabolism and bone homeostasis. In line with previous studies, majority of students (94%) correctly reported that vitamin D deficiency could lead to bone and skeletal disorders [
Apart from adequate sun exposure, fortified milk and other food products (salmon, cod liver oil, sundried mushrooms, and egg yolk) are rich in vitamin D. We observed that students need to have knowledge about natural, dietary, and fortified sources and that these dietary sources alone are insufficient in treatment of deficient states. In our population, as in previous studies [
With regard to the amount of dietary intake of vitamin D, only one-third of respondents correctly identified the RDA of vitamin D. Institute of Medicine (IOM), USA, recommends RDA of 600 IU daily for adult male and females to optimise bone health. However, in absence of adequate vitamin D intake, insufficiency or deficiency may result. US Endocrine Society Classification guidelines suggest that vitamin D (25-hydroxycholecalciferol) serum levels in an adult indicate insufficiency at 20–29 ng/mL and deficiency at <20 ng/mL (Table
Vitamin D status in relation to 25 (OH)
IOM (Institute of Medicine) | |
---|---|
Severe deficiency | <5 ng/mL |
Deficiency | <15 ng/mL |
Sufficiency | >20 ng/mL |
Risk of toxicity | >50 ng/mL |
|
|
US Endocrine Society Classification | |
|
|
Deficiency | <20 ng/mL |
Insufficiency | 21–29 ng/mL |
Sufficiency | >30 ng/mL |
Toxicity | >150 ng/mL |
Treatment in the right form of vitamin D supplement, adequate dose, and duration is imperative to prevent long-term health consequences of vitamin D deficiency or toxicity [
Results of the current study are largely consistent with those conducted in other countries when it comes to identifying a knowledge deficit [
This research evidence has reinforced the need for sensitization of medical undergraduates early in their training regarding vitamin D, its importance, and prevention and treatment of deficiency. Awareness about vitamin D at this stage of medical profession would not only benefit their own health but also instill a health-related behaviour change and increased awareness and knowledge as future medical practitioners [
Results of this study, if extrapolated to general population, could indicate a gross lack of knowledge about this worldwide pandemic and how to prevent it at an individual level. In order to facilitate health-related behaviour change, program planners need to start with an exploration of the target population’s needs, which includes understanding of their knowledge about the specific issue of interest (i.e., vitamin D) [
The key strengths of this study include an important research question, the outcome of which could not only affect the study population, that is, medical students but indirectly also impact the general population/patients that they would treat as future medical practitioners. The results of this study will make an important contribution by defining and providing an evidence base for the existing knowledge deficit and instituting corrective measures at a crucial step of medical training. However, results may not be generalizable to all student populations as our sample was derived from a single superspeciality tertiary health care centre in India. The cross-sectional nature of our study limited subsequent assessment and translation of the imparted knowledge into practice. In addition, the questionnaire was primary developed for this study and was not used or validated beyond the context of the present study.
Our study highlighted a lack of awareness about the importance of vitamin D, worldwide prevalence of vitamin D deficiency, and its management among medical students. This knowledge deficit could provide baseline data to design training modules for medical professionals that would help them in identification, prevention, and treatment of vitamin D deficiency. Increased awareness at an early stage of medical training could instill adoption of health-related behaviours at personal and professional level. Effective educational campaigns targeted to specific populations would increase awareness about adequate intake of vitamin D, thereby improving overall health.
The authors declare that there are no conflicts of interest regarding the publication of the paper.