ORIGINAL ARTICLE  
Role of Vitamin D in Near Sightedness  
Yasir Iqbal1, Aqsa Malik2, Rabbia Shabbir3, Atteaya Zaman4, Masooma Talib5  
1,5Watim Medical and Dental College, Rawat, Rawalpindi, 2Department of Biochemistry, Medical College, Mirpur,  
3Department of Biochemistry, HITEC. IMC Dental College, Taxilla, 4Federal Medical and Dental College,  
Islamabad  
ABSTRACT  
Purpose: To determine the levels of Vitamin D in children with myopia and to compare them with age matched  
controls.  
Study Design: Case control study.  
Place and Duration of Study: The study was conducted in Naseer Memorial Hospital, Dadhyal Azad Kashmir  
from March 2016 to March 2017.  
Material and Methods: Two hundred patients were selected using convenient sampling technique and were  
divided two groups (group I Myopic and group II control). Myopia was labeled if after subjective refraction a  
Spherical Equivalent (SE) of −0.50 diopters (D) or more was found. Vitamin D levels were measured by  
radioimmunoassay technique with Diasorin SR® kit following the user’s manual. Vitamin D levels less than  
20 ng/ml were considered Vitamin D deficient following the standards of American academy of pediatrics. The  
collected data was entered in the statistical package for social sciences (SPSS) version 21 for analysis.  
Independent t–test was used to determine the significant difference of means between controls and patients.  
P-values less than 0.05 were considered significant.  
Results: Mean age of controls and myopes were 10.65 ± 3.9 and 10.20 ± 2.5 years respectively. Vitamin D  
levels in myopic children were found to be 14.95 ± 3.75 ng/ml and there was no significant difference in mean  
values of Vitamin D levels in myopic and control group.  
Conclusion: We found no difference in Vitamin D levels of myopic and non myopic children and concluded that  
Vitamin D has no role in development or progression of myopia.  
Key Words: Vitamin D, Myopia, Refractive error, Objective refraction.  
How to Cite this Article: Iqbal Y, Malik A, Shabbier R, Zaman A, Zia S, Talib M. Role of Vitamin D in Near  
Sightedness, Pak J Ophthalmol. 2020; 36 (2): 137-141.  
Doi: 10.36351/pjo.v36i2.990  
can be classified as physiologic and pathologic. The  
cause of physiological myopia can be high curvature  
INTRODUCTION  
Types of refractive errors are myopia, hyperopia and  
astigmatism1. In Myopia, the person is able to see near  
of the cornea, nuclear sclerosis and elongated eyeball  
or combination of these factors with the absence of  
objects and the distant ones are blurry hence the term  
any other ocular pathology3. The cause of pathologic  
near sightedness. It can occur at any age like in  
myopia is abnormal lengthening of the eyeball leading  
childhood or adolescence and even in old age. There is  
no gender predisposition and is affected globally2. It  
to thinning of the sclera wall and other complications.  
Another classification is based on age of onset. It tends  
to run in the families2 and no occupational association  
Correspondence to: Yasir Iqbal  
Associate Professor of Ophthalmology,  
Watim Medical and Dental College, Rawat, Rawalpindi  
Email: yazeriqbal@gmail.com  
has been found.  
Myopia is prevalent in 20% of the population  
worldwide and is estimated that 12% children are  
137  
Pakistan Journal of Ophthalmology, 2020, Vol. 36 (2): 137-141  
Role of Vitamin D in Near Sightedness  
affected2. In Pakistan its prevalence is 6% in adults4  
and in children it is reported as high as 21%5. The  
figure is on the rise every year and is presenting as  
major global health problem2. Not only it has a social  
impact on the individual, making the person unable to  
perform the tasks of desire, it acts as a factor in adding  
individuals with less productivity6. Furthermore,  
myopia is a risk factor for other visually blinding  
diseases like glaucoma3 and retinal detachment3 which  
further implicates on the health system. For these  
reasons the pathophysiology of development of  
myopia remained a hot debate since ages.  
whether Vitamin  
pathophysiology or not.  
D
has  
a
role in myopia  
MATERIAL AND METHODS  
It was an observational case-control study conducted  
at Naseer Memorial Hospital, Dadyal Azad Kashmir,  
from March 2017 to March 2019. The study was  
conducted according to the guidelines of Declaration  
of Helsinki. A formal verbal consent from the children  
and their parents was taken before the commencement  
of the study. After fulfilling the inclusion and  
exclusion criteria, patients were selected using  
convenient non-probability sampling technique and  
were divided two groups (group I Myopic and group II  
control). Selection criteria for group I was; children of  
any gender with age between 5 to 15 years and  
diagnosed with physiological myopia. Group II were  
age-matched controls. Subjects with history of ocular  
surgery, eye diseases like glaucoma, uveitis, retinal  
disease, cataract, systemic disease, any therapeutic  
regimen or steroid use were excluded from the study.  
Demographic information i.e., age, gender and history  
of systemic disorders were recorded. Children  
underwent complete ocular examination including  
visual acuity, detailed slit lamp examination,  
intraocular pressure measurement and ophthalmoscopy  
before cycloplegic retinoscopy was done. Myopia was  
labeled if after subjective refraction a Spherical  
Equivalent (SE) of −0.50 diopters (D) or more was  
found (Mild myopia if SE less than −3.0 D; moderate  
myopia if greater than or equal to −3.0 D; and high  
myopia was defined as more than or equal to −6.0 D).  
Children with myopia were included in group I  
whereas those having astigmatism and hyperopia was  
excluded. Children with no refractive error were  
included in the control group.  
The pathophysiology of myopia had been  
associated with many myths. Reading books in dim  
light or while lying on bed, watching too much  
television and even deficiency of Vitamin A had been  
proclaimed but no scientific reason was found. Some  
researchers advocate genetic predisposition7and have  
identified numerous genetic loci linked with myopia  
whereas others have attributed to less outdoor activity  
and Vitamin D deficiency8.  
Vitamin D, once considered a Vitamin, is now  
being treated as a hormone. Many studies have  
demonstrated Vitamin D having effects on biological  
processes like calcium and phosphorus metabolism  
regulation as well as cell proliferation and  
differentiation,  
immune  
regulation  
and  
neurogenesis9,10. It is found to be associated with  
cardiovascular diseases, cancers, autoimmune and  
infectious diseases. About 90% of the Vitamin D is  
derived from the skin and around 10% from diet.  
There are two forms of Vitamin D, Vitamin D3  
(cholecalciferol) and Vitamin D2 (ergocalciferol).  
Vitamin D3 is derived from the skin after exposure to  
ultraviolet light. After absorption from intestines and  
the synthesis by skin, Vitamin D is converted into  
25 (OH) D in the liver. If the 25 (OH) D levels are  
greater than or equal to 30 ng/ml it is considered as  
normal and less than this is considered as Vitamin D  
deficiency11.  
Informed consent was taken from the parents of all  
participants. For assessment of Vitamin D levels, 2cc  
of venous blood was collected and after centrifugation  
serum was stored at −20°C temperature in laboratory  
freezer for further analysis. Vitamin D levels were  
measured by radioimmunoassay technique with  
Diasorin SR® kit following the user’s manual.  
Vitamin D levels less than 20 ng/ml were considered  
Vitamin D deficiency following the standards of  
American academy of pediatrics.  
Recently time spent outdoors has become area of  
interest in myopia research. Researchers have found  
low incidence of myopia in those who spent more time  
outdoors as compared to the ones who are more  
involved in indoor activities, which led to the concept  
that Vitamin D might be a possible moderator of this  
association8. Researchers have reported high incidence  
of myopia in children aged 5 to 15 years12. Therefore,  
in this study we compared Vitamin D levels of myopic  
and non-myopic children in order to determine  
The collected data was entered in the statistical  
package for social sciences (SPSS) version 21 for  
analysis. Gender was expressed as percentages and  
Pakistan Journal of Ophthalmology, 2020, Vol. 36 (2): 137-141  
138  
Yasir Iqbal, et al  
frequency whereas numerical variables like age and  
Vitamin D levels were expressed as mean and standard  
deviation. Independent t–test was used to determine  
the significant difference of means between controls  
and patients. P values less than 0.05 was considered as  
significant.  
was proposed that better quality of retinal image is  
attained while viewing distant objects with a small  
pupil size and accommodative errors may be inhibiting  
ocular growth and decreasing the risk of myopia17.  
However, evidence from animal models did not  
support this hypothesis. Another proposed hypothesis  
was an increase in retinal dopamine secretion in  
response to bright light during outdoors suppresses  
axial elongation but again no scientific evidence was  
presented.  
RESULTS  
A total of 1587 children in between the age of 5 – 15  
years were examined during the study period. After  
fulfilling the inclusion /exclusion criteria, 100 children  
were selected by simple convenient sampling method  
for each group. Group I consisted of 47.18% males  
and 52.11% females whereas in group II were 55.82%  
males and 44.17% females. The mean ages of controls  
and myopics were 10.65 ± 3.9 and 10.20 ± 2.5 years  
respectively. The age difference between the two  
groups was statistically insignificant (Table 1). In  
group I, 79.4% had mild myopia, 19.6% had moderate  
myopia and 0.6% had high myopia. The Vitamin D  
levels in myopic children were found to be 14.95 ±  
3.75 ng/ml and there was no significant difference in  
mean values of Vitamin D levels in myopic and  
control group.  
Vitamin D is a vital element for absorption of  
calcium in the intestines and plays a significant role in  
the growth of bones along with mineral and Calcium  
homeostasis9. The commonly used indicator of  
Vitamin D status is serum 25 (OH) D concentrations.  
Researchers have found a strong association between  
serum 25 (OH) D concentrations and myopia  
advocating greater time spent outdoors reduces the risk  
of myopia. Sherwin JC et al8 reported low serum  
concentrations of Vitamin D in myopes. Similarly, low  
Vitamin D concentration was reported by Tideman JW  
et al16 in patients with high axial length. How Vitamin  
D prevents myopia remains to be answered. One  
theory is that, as deficiency of Vitamin D leads to  
alteration of intracellular Ca level and subsequently  
causes impaired contraction and relaxation of the  
ciliary muscles thus leading to myopia18. Another  
theory is Calcium deficiency secondary to lack of  
adequate Vitamin D levels leading to head and orbit  
deformity and consequently myopia of prematurity but  
against this was the finding of no change in refractive  
status of low birth weight infants after extra-enteral Ca  
supplementation18. Vitamin D is also thought to affect  
pathological scleral growth and myopia via retinoic  
acid. Retinoic acid and Vitamin D receptors form  
heterodimers which participate in signaling and cell-  
cycle regulation but data based studies are lacking17.  
Table 1: Descriptive Statistics for the Myopia and Control.  
Group I  
(Myopia)  
n = 100  
Group II  
(Control)  
n = 100  
P-value  
Mean Age  
(years ± SD)  
10.20 ± 2.5 10.65 ± 3.9  
0.789  
Male  
Female  
47.18%  
52.11%  
55.82%  
44.17%  
0.675  
0.647  
Gender  
Serum Vitamin D  
levels (ng/ml)  
Spherical equivalent  
refractive error (D)  
15.95 ± 3.75 16.02 ± 5.11  
-3.08 ± 2.45 +0.25 ± 0.26  
0.625  
Not  
applicable  
In our study, we found no difference in Vitamin D  
levels of myopics and age matched control. Same  
finding was reported by another researcher, according  
to whom myopes prefer to stay indoors and  
consequently have low 25 (OH) D3 levels therefore  
serum 25 (OH) D3 is simply a biomarker of sun  
exposure19. Hence outdoor activity might be mediating  
myopia prevention via some other pathway instead of  
Vitamin D. Analysis done by Williams KM et al20 also  
negated the hypothesis that outdoor activity protects  
against myopia by Vitamin D levels. Furthermore,  
Williams KM et al20 objected that if outdoor activity is  
protective against myopia it should slow the  
DISCUSSION  
The pathogenesis of myopia has been a hot debate  
since ages. Its association with excessive near work  
and less outdoor activity has been advocated by  
many13. Atta Z et al14 found myopia in 52.6% of the  
children studying in madrasas and proposed less  
outdoor activity to be associated with myopia.  
Similarly, Pan CW15 found that children involved  
more in outdoor activity have less chances of myopia.  
Similar idea was advocated by Tideman JW et al16.  
But the question remained unanswered that how  
outdoor activity affects refractive error development. It  
139  
Pakistan Journal of Ophthalmology, 2020, Vol. 36 (2): 137-141  
Role of Vitamin D in Near Sightedness  
progression in those who already have myopia. These  
questions are yet to be answered.  
Rabbia Shabbier; Lecturer: Study design, Final review.  
Atteaya Zaman, Assistant Professor: Study design,  
In our study the participants had below normal  
mean 25 [OH] D concentrations and were below the  
accepted normal value of 20 ng/ml. This is in contrast  
to other studies15,16 in which only myopes had low  
levels of Vitamin D. This might be due to other factors  
like ethnicity, outdoor activity and diet. Vitamin D  
deficiency is reported more in African Americans  
compared to Caucasians and more in the regions of  
Middle East, China, Mongolia, and the Indian  
subcontinent21. The confounder of ethnicity was not  
addressed in our study. Likewise, high Vitamin D  
levels and less incidence of myopia is advocated to be  
associated with more outdoor activity15 and to higher  
dietary intake of Vitamin D16 but Mutti et al17 found  
no association. According to Mutti et al17 the  
prevalence of myopia is on the rise in Asian  
population despite the Vitamin D rich fish diet.  
Therefore, further researchis needed to identify  
relevant biological connections between Vitamin D  
and myopia. The diet confounder was also not taken  
into account in our study.  
Final review.  
Masooma Talib; Assistant Professor: Study design,  
Final review.  
REFERENCES  
1. Iqbal Y, Niazi FK, Niazi MA. Frequency of Eye  
Diseases in School Age Children. Pak J Ophthalmol.  
2009; 25 (4).  
2. Morgan I, He M, Saw S, Krueger R, Lam D. Myopia.  
Asia Pac J Ophthalmol. 2016; 5 (6): 383-5.  
3. Kumar A, Chawla R, Kumawat D, Pillay G. Insight  
into high myopia and the macula. Indian J Ophthalmol.  
2017; 65 (2): 85-91.  
4. Abdullah AS, Jadoon MZ, Akram M, Awan ZH,  
Azam M, Safdar M, Nigar M. Prevalence of  
uncorrected refractive errors in adults aged 30 years and  
above in a rural population in Pakistan. J Ayub Med  
Coll. 2015; 27 (1): 8-12.  
5. Latif MZ, Khan MA, Afzal S, Gillani SA,  
Chouhadry MA. Prevalence of refractive errors;  
evidence from the public high schools of Lahore,  
Pakistan. J Pak Med Assoc. 2019; 69 (4): 464-467.  
6. Guo W, Woodward MA, Heisler M, Blachley T,  
Corneail L, Cederna J, Kaplan AD, Casey PA. Risk  
factors for visual impairment in an uninsured  
population and the impact of the Affordable Care Act.  
Clinics in Surgery, 2016; 134: 802-809.  
7. Li M, Zhai L, Zeng S, Peng Q, Wang J, Deng Y, Xie  
L, He Y, Li T. Lack of association between LUM  
rs3759223 polymorphism and high myopia. Opt Vis  
Sci. 2014; 91 (7): 707-12.  
Limitation of the study is that it was an  
observational study not a randomized trial. The  
confounding factors like time spent outdoors, seasonal  
variation of measurement and sunlight exposure,  
dietary habits and demographic variables were not  
taken into account.  
CONCLUSION  
8. Sherwin JC, Hewitt AW, Coroneo MT, Kearns LS,  
Griffiths LR, Mackey DA. The association between  
times spent outdoors and myopia using a novel  
biomarker of outdoor light exposure. Invest Ophthalmol  
Vis Sci. 2012; 53 (8): 4363-70.  
We found no difference in Vitamin D levels of myopic  
and non myopic children and concluded that Vitamin  
D has no role in development or progression of  
myopia.  
9. Bhatt N, Ali A, Waly MI. Non-Skeletal Benefits of  
Vitamin D. Canad J Clin Nutr. 2019; 7 (1): 141-59.  
10. Meehan M, Penckofer S. Role of Vitamin D in aging  
adult. J Aging Gerontol. 2014; 2 (2): 60–71.  
11. Tangpricha V, Koutkia P, Rieke SM, Chen TC,  
Perez AA, Holick MF. Fortification of orange juice  
with vitamin D: a novel approach for enhancing vitamin  
D nutritional health. Am J Clin Nutr. 2003; 77 (6):  
1478-83.  
Ethical Approval  
The study was approved by the Institutional review  
board/Ethical review board.  
Conflict of Interest  
Authors declared no conflict of interest  
12. Wu PC, Huang HM, Yu HJ, Fang PC, Chen CT.  
Epidemiology of myopia. The Asia Pac J Ophthalmol.  
2016; 5 (6): 386-93.  
13. Polling JR, Verhoeven VJ, Tideman JW, Klaver  
CC. Duke-Elder’s views on prognosis, prophylaxis, and  
treatment of myopia: way ahead of his time.  
Strabismus, 2016; 24 (1): 40-3.  
Authors’ Designation and Contribution  
Yasir Iqbal; Associate Professor: Study design, Data  
Collection, Manuscript Writing, Final review  
Aqsa Malik; Assistant Professor: Study design,  
Manuscript Writing, Final review.  
Pakistan Journal of Ophthalmology, 2020, Vol. 36 (2): 137-141  
140  
Yasir Iqbal, et al  
14. Atta Z, Arif AS, Ahmed I, Farooq U. Prevalence of  
refractive errors in Madrassa students of Haripur  
district. J Ayub Med Coll. 2015; 27 (4): 850-2.  
15. Pan CW, Qian DJ, Saw SM. Time outdoors, blood  
Vitamin D status and myopia: a review. Photoch  
Photobio Sci. 2017; 16 (3): 426-32.  
16. Tideman JW, Polling JR, Voortman T, Jaddoe VW,  
Uitterlinden AG, Hofman A, et al. Low serum  
Vitamin D is associated with axial length and risk of  
myopia in young children. Eur J Epidemiol. 2016; 31  
(5): 491-9.  
calcium supply. J Pediat Gastroenterol Nutr. 2011; 53  
(3): 339.  
19. Guggenheim JA, Williams C, Northstone K, Howe  
LD, Tilling K, St Pourcain B, et al. Does Vitamin D  
mediate the protective effects of time outdoors on  
myopia? Findings from a prospective birth cohort.  
Invest Ophthalmol Vis. Sci. 2014; 55 (12): 8550-8.  
20. Williams KM, Bentham GC, Young IS, McGinty A,  
McKay GJ, Hogg R, et al. Association between  
myopia, ultraviolet  
B radiation exposure, serum  
Vitamin D concentrations, and genetic polymorphisms  
in Vitamin D metabolic pathways in a multicountry  
European study. JAMA Ophthalmology, 2017; 135 (1):  
47-53.  
17. Mutti DO, Marks AR. Blood levels of Vitamin D in  
teens and young adults with myopia. Opto Vis Sci.  
2011; 88 (3): 377.  
21. Van Schoor NM, Lips P. Worldwide Vitamin D status.  
Best Pract Res Clin Endocrinol Metab. 2011; 25 (4):  
671-80.  
18. Carroll WF, Fabres J, Nagy TR, Frazier M, Roane  
C, Pohlandt F, et al. Results of extremely low birth  
weight infants randomized to receive extra enteral  
.…….  
141  
Pakistan Journal of Ophthalmology, 2020, Vol. 36 (2): 137-141