European Journal of Cardiovascular Medicine

Vitamin D is a fat soluble vitamin. There are two major biologically inert precursors of vitamin D cholecalciferol and ergocalciferol. Cholecalciferol is formed in the skin when exposed to sun light UVB rays and ergocalciferol is plant derived, produced exogenously by  irradiation of ergosterol and enters the circulation through the diet.[1]

Vitamin D that comes from the skin or diet is biologically inert and requires its first hydroxylation in the liver by the enzyme 25-hydroxylase to 25(OH)Vitamin D. However, 25(OH)Vit D requires a further hydroxylation in the kidneys by the 25(OH)D-1-OHase enzyme to form the biologically active form of vitamin D 1,25(OH)2D. [2]

The hormonal form of Vitamin D (1,25-dihydroxyvitamin D) acts through a nuclear receptor to carry out its many function including calcium absorption, phosphate absorption in the intestine, calcium mobilization in bone and calcium reabsorption in the kidney. It also has several noncalcemic functions in the body. [3] With the discovery of Vitamin D receptors in various tissues several other biological functions of Vitamin D are increasingly recognized and its role in many human disease like cancer, diabetes, hypertension, cardiovascular and autoimmune and dermatological diseases is being extensively explored. The non classical functions of Vitamin D involves regulation of cellular proliferation, differentiation, apoptosis and innate and adaptive immunity. [4]

The mechanism of action of calcitriol is mediated by the vitamin D receptor, a subfamily of nuclear receptors that act as transcription factors into the target cells after forming a heterodimer with the retinoid X receptor. This kind of receptors has been found in virtually all cell types which may explain its multiple actions on different tissues. [5]

Vitamin D deficiency affects person of all ages. Common manifestations of vitamin D deficiency are low back pain, proximal muscle weakness, muscle aches and throbbing bone pain elicited with pressure over sternum or tibia. [6]. Serum concentration of 25 hydroxy vitamin D is currently the main indicator of vitamin D status. It reflects vitamin D produced endogenously. In serum 25 hydroxy vitamin D has a fairly long half life of 15days [7]. A 25-hydroxyvitamin D level should be obtained in patients with suspected vitamin D deficiency. Deficiency is defined as serum 25-hydroxy vitamin D level of less than 20ng per ml and insufficiency is defined as a serum 25-hydroxyvitamin D level of 20 to 30ng per ml. [6,8] The health benefits of vitamin D sufficiency are clear, awareness of the dangers of vitamin D deficiency is lacking. People with vitamin D deficiency have no obvious symptoms until it is severe. [9]

Risk factors for Vitamin D deficiency include decreased sun exposure, decreased dietary intake, malabsorption syndromes such as celiac disease, short bowel syndrome, gastric bypass, inflammatory bowel disease, chronic pancreatic insufficiency and cystic fibrosis. Also conditions associated with decreased endogenous synthesis like chronic liver disease and renal failure. Certain drugs which increase hepatic catabolism such as Phenobarbital, carbamazepine, dexamethasone, nifedipine, spironolactone, clotrimazole and rifampicin which activate degradation of Vitamin D. [10]

This was a Cross-sectional study done over a period of 6months from march 2024 to august 2024, at East point college of medical sciences and research centre, Bangalore. Participants from this institution satisfying the inclusion criteria will be included in the study. Institutional ethical committee approval was obtained for the study ( EPCMSRC/ADM/IEC/2023-24/65) and informed written consent was obtained from all study subjects.

Sample size calculation

Sample size and the basis for the same according to a study done by Ray S., eta. al on Vitamin D deficiency among health professionals in Kolkata in 2020, the prevalence of Vit D was 73% [11]  hence using the formula n = z² 1-a/2 x  p (1-p)/d²   , where, n= sample size, p -= 0.73, 1-p = 0.27. d= absolute precision = 10% = 0.1;  z² 1-a/2  = constant at 1.96

n= 1.96 x 1.96x 0.73 x 0.27/ 0.1 x 0.1 = 0.75717/0.01 = 75

The minimum required sample size is 75.

Inclusion Criteria:

Participants aged more than 18years who work at East point hospital, doctors, nurses and other staff were included in the study, those who are not under exclusion criteria.

Exclusion Criteria:

1. Known case of chronic kidney disease defined by Serum Creatinine >1.5 mg/dl
2. Known case of chronic liver disease or hepatic dysfunction having ALT & AST >2.5 times upper level of normal value.
3. Malabsorption including history of inflammatory bowel disease, small bowel or gastric surgery.
4. Diseases associated with altered bone metabolism (Hyperthyroidism, Hyperparathyroidism, Type 1 Diabetes mellitus). 
5. Known metabolic bone diseases.
6. Treatment with medications that interfere with Vitamin D metabolism (Anticonvulsants, Rifampicin, Glucorcorticoids) either taking actively or have taken more than 2 weeks during previous months. [11]

METHODOLOGY:
After taking informed consent from the participants, each subject was interviewed personally by the investigator and their physical examination was carried out. Data regarding age, sex, body weight, height, and body mass index (BMI) were recorded from each subject. Also information regarding physical activity, sun light exposure and use of sun screen was obtained.  Serum Vitamin D levels were estimated using chemi luminescent immuno assay (CLIA) method. Vitamin d levels recorded and less than 20ng/ml was taken as deficiency and levels 20 to 30ng/ml was taken as insufficiency and levels more than 30ng/ml taken as sufficient levels. The prevalence of vitamin D deficiency among health care workers was estimated. Association between Vitamin D status and factors like age, sex, physical activity, BMI , sun exposure was investigated.

STATISTICAL METHOD:

Data was entered in MS EXCEL file; analyzed using SPSS software version 21. All descriptive statistics were represented with percentages, Mean with SD, independent sample t test, fisher’s exact test were applied to find significance. P<0.05 was considered as statistically significant.

Total 75 participants were included in the study.  Doctors, nurses and health workers were included in the study. Among 75 subjects included in the study, almost same number were found among both the sex, 38(51%)were female and 37 (49%) were male. The mean value of age of study subjects was 45.55±13.88 years. 43(58%) subjects were having vitamin D deficiency (less than 20ng/ml) and 22 (29%) subjects were found to have insufficient vitamin D levels. 65 out of 75 (87%) subjects were either deficient or insufficient of vitamin D. (table/fig 1). Only 10 out of 75 (13%) had sufficient vit D levels. (table/fig 2)

Table/fig 1

Table/Fig 2

Severely vitamin D deficiency defined as less than 10ng/ml. [12]. So we can divide them into 3 groups. insufficient vitamin D as 20-30ng/ml, moderately deficient as 10-19ng/ml and Severely deficient as less than 10ng/ml.  Among 87% subjects whose vitamin D levels less than 30ng/ml, insufficient was present in 34% (22 out of 65) of study subjects, moderate deficiency was present in 57% (37 out of 65) of study subjects and 9% (6 out of 65) of study subjects had severe vitamin D deficiency .(Table/fig 3)

Table/fig 3

Table/fig:4

Sun exposure per day were categorised into 3 groups. Exposure less than 30minutes, 30 to 60 minutes and more than 60minutes. It was found that mean Vitamin D levels were less in the group were sunlight exposure were less than 30min. (table/fig 4)

Table/fig:5 Performing Fisher-Freeman-Halton Exact Test between Vitamin D levels and Sun exposure per day

There was a statistically significant association between vitamin D levels and sun light exposure per day done by Fisher Freeman Halton Exact test.(table/fig 5)

Table/fig:6

Data regarding sun screen use also were collected from the participants. 61% of the participants were never used sun screen. 31% were using once a day and 8% were using twice a day or more. It was found that slightly less vit D levels were observed in the group where sun screen use were used twice a day or more.(table/fig 6). Although there was no statistically significant association between vitamin D levels and sun screen use, done by Fisher Freeman Halton Exact test.(table/fig 7)

Table/fig:7

Majority of the study subjects were of overweight 75% (56) and only 25% (19) of the study subjects were normal weight.

Table/fig:8

Performing Fisher-Freeman-Halton Exact Test between Vitamin D levels and BMI

Not Statistically significant

Vitamin D deficiency is more common than previously thought and has received interest because of evidence for the non-skeletal effects of vitamin D and widespread global deficiency.

In the present study, the health care professionals were discovered to have a high prevalence of vitamin D insufficiency.

In a multicentric study done in India, confirms the high prevalence of vitamin D deficiency all across India in apparently healthy, middle-aged health care professionals with Mean (±SD) age of subjects was 42.71 ± 6.8 years. Seventy-nine percent of subjects were deficient, 15 % were insufficient, and just 6 % were sufficient in vitamin D status.[13] where as in our study with the mean value of age of study subjects was 45.55±13.88 years, 58% of subjects were having vitamin D deficiency and 29% of  subjects were found to have insufficient vitamin D levels and only 13%  had sufficient vit D levels.

In a study done at Saudi arabia by Al-Elq AH, in healthy medical students, it was found that no one had an optimal Vitamin D levels  [14].Our findings reveal a significant prevalence of vitamin D deficiency and insufficiency among this population, with 87% of participants exhibiting levels below the recommended threshold.

Several reasons have been suggested for the comparatively reduced vitamin D levels in women such as spending extended periods indoors, using sunscreen, insufficient sun exposure, pregnancy, and breastfeeding [15].

An important finding is the link between exposure to sunlight and levels of vitamin D. Those who had limited sun exposure, less than 30 minutes per day, had notably lower levels of vitamin D in comparison to those who spent more time in the sun. This highlights the crucial role of sufficient sunlight exposure in ensuring ideal vitamin D levels. Moreover, although the use of sunscreen did not demonstrate a notable effect on vitamin D levels, individuals who applied sunscreen two or more times per day had slightly decreased levels.

The findings of this cross-sectional study underscore a markedly high prevalence (87%) of vitamin D insufficiency and deficiency among healthcare professionals, despite their presumed awareness of health risks and preventive care. The lack of significant associations between serum 25(OH)D levels and demographic or anthropometric variables such as age, sex, BMI, and physical activity suggests that these are not primary determinants in this cohort. However, a statistically significant inverse relationship was identified between daily sunlight exposure and vitamin D status (p = 0.01), indicating that inadequate cutaneous synthesis due to limited UVB exposure is a key etiological factor. The asymptomatic presentation in the majority of participants highlights the insidious nature of hypovitaminosis D and reinforces the importance of proactive screening, even in ostensibly low-risk groups such as healthcare workers. These data support the implementation of institution-level interventions including awareness campaigns, structured screening protocols, and targeted supplementation strategies to mitigate the risk and downstream complications associated with chronic vitamin D deficiency.

1. RanZhang, Declan P Naughton, Vitamin D in health and disease: current perpectives. Nutrition journal, dec 2010.
2. Rathish nair, Arun Maseeh, Vitamin D:The sunshine vitamin . J Pharmacolpharmacother. 2012 apr-jun; 3(2): 118-126
3. Deluca Hector F. overview of general physiologic features and functions of Vitamin D, The American Journal of Clinical Nutrition, vol 80, Issue 6, Dec 2004, page 1689-1696.
4. Meenakshi Umar, konduru S Sastry and Aouatef I Chouchane; Role of vitamin D Beyond the skeletal function: A review of the molecular and clinical studies. Int J Mol sci. 2018 jun; 19(6): 1618
5. Angel Gil, Julio Plaza Diaz, Maria Dolores Mesa; Vitamin D classic and novel actions. Annals of nutrition and metabolism, 2018;72:87-95
6. Paula Bordelon, Maria V.Ghetu, Robert Langan; Recognition and management of Vitamin D deficiency. American family physician, 2009; vol 80:number 8.
7. Vitamin D fact sheet for health professionals. National institute of health, office of dietary supplements. U.S. department of health and human services.
8. Michael F Holick, Neil C Binkley, Heike A et al; Evaluation, treatment and prevention of Vitamin D deficiency: an endocrine society clinical practice guideline. Journal of clinical endocrinology and metabolism, 2011; vol 96: issue 7: 1911-1930
9. Micheal F Holick. Defciency of sunlight and Vitamin D. BMJ,2008 jun 14; 336(7657):1318-1319
10. Omeed Sizar, Swapnil khare, Amandeep Goyal, Amy Givler; Vitamin D deficiency. Treasure island, star pearls publishing. July 2023.
11. Saswati Ray, Asis Mitra, Kingshuk Bhattacharjee. Prevalence of Vitamin D deficiency among health care professionals in medical colleges of India. Journal of diabetes, metabolic disorders and control. 2020; 7(2):42-45.
12. Kurt A. Kennel, Matthew T.Drake, Daniel L.Hurley. Vitamin D deficiency in Adults. Mayo clinic proceedings. August 2010; 85(8):752-758.
13. Maria Beloyartseva , Ambrish Mithal, Parjeet Kaur, Sanjay Kalra, Manash P Baruah, Satinath Mukhopadhyay, Ganapathy Bantwal, Tushar R Bandgar. Widespread vitamin D deficiency among Indian health care professionals. Arch Osteoporos.2012:7:187-92
14. Al-Elq AH. The status of Vitamin D in medical students in the pre-clerkship years of a Saudi medical school. J FamCommunity Med 2012; 19:100-4.
15. Holick MF. Resurrection of vitamin D deficiency and rickets. J Clin Invest. 2006;116(8):2062-72.