Effects of vitamin A supplementation on visual function in healthy adults: A systematic review

Background. Vitamin A plays an important role in various bodily functions, including vision. This systematic review aimed to synthesize the available evidence on the effects of vitamin A supplementation on visual function in healthy adults. Methods. A comprehensive search of electronic databases wa...

Full description

Saved in:
Bibliographic Details
Main Authors: Kavous Shahsavarinia, Ali Mostafaei, Nooshin Milanchian, Leila Roshangar, Parastu Fallahi, Moloud Balafar, Robab Mehdipour, Fereshteh Farhadi, Hassan Soleimanpour, Nasim Hajipoor, Reza Mohammadi, Hanieh Salehi-Pourmehr
Format: Article
Language:fas
Published: Tabriz University of Medical Sciences 2025-06-01
Series:مجله پزشکی دانشگاه علوم پزشکی تبریز
Subjects:
Online Access:https://mj.tbzmed.ac.ir/PDF/mj-47-124.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849415462235930624
author Kavous Shahsavarinia
Ali Mostafaei
Nooshin Milanchian
Leila Roshangar
Parastu Fallahi
Moloud Balafar
Robab Mehdipour
Fereshteh Farhadi
Hassan Soleimanpour
Nasim Hajipoor
Reza Mohammadi
Hanieh Salehi-Pourmehr
author_facet Kavous Shahsavarinia
Ali Mostafaei
Nooshin Milanchian
Leila Roshangar
Parastu Fallahi
Moloud Balafar
Robab Mehdipour
Fereshteh Farhadi
Hassan Soleimanpour
Nasim Hajipoor
Reza Mohammadi
Hanieh Salehi-Pourmehr
author_sort Kavous Shahsavarinia
collection DOAJ
description Background. Vitamin A plays an important role in various bodily functions, including vision. This systematic review aimed to synthesize the available evidence on the effects of vitamin A supplementation on visual function in healthy adults. Methods. A comprehensive search of electronic databases was conducted to identify randomized controlled trials investigating the effects of vitamin A supplementation on visual function in healthy adults. The methodological quality of the included studies was assessed using the Cochrane Collaboration tool. Data extraction and analysis were performed to determine the overall effect of vitamin A supplementation on visual outcomes. Two reviewers independently assessed the studies for biases, with disagreements resolved by a third reviewer. The quality of the articles was evaluated in accordance with existing standards, with any disagreements resolved through discussion or referral. Results. A search of 12945 articles from databases led to 276 full-text articles being evaluated, resulting in 17 studies. These studies examined the effects of lutein and zeaxanthin supplementation on macular pigment optical density (MPOD) and visual function. Results showed a positive correlation between MPOD and temporal contrast sensitivity function, with both improving after supplementation. However, a study by Bartlett did not find significant improvements in visual function. Most studies showed positive effects on MPOD and visual function, but the clinical significance and optimal dosage and duration remain unclear. Most studies had medium to high quality evidence. Conclusion. Vitamin A, Lutein, and zeaxanthin supplementation may improve visual function, but optimal dosage, duration, and carotenoid combination are not yet established. Long-term safety and efficacy require further investigation, including standardized assessments, longer follow-ups, diverse populations, and mechanistic studies. Practical Implications. While current research indicates that supplementing with lutein and zeaxanthin may offer benefits like improved contrast sensitivity and macular pigment density, the inconsistent findings highlight that we don't yet have a clear understanding of who will benefit most, the ideal dosage, or how long supplementation is effective for healthy adults. Therefore, widespread recommendations for these supplements to enhance vision in the general healthy population cannot be made at this time, and individuals should consult with healthcare professionals before starting any supplementation.
format Article
id doaj-art-c3a3a28e3ca547ff96a5f3d031247e55
institution Kabale University
issn 2783-2031
2783-204X
language fas
publishDate 2025-06-01
publisher Tabriz University of Medical Sciences
record_format Article
series مجله پزشکی دانشگاه علوم پزشکی تبریز
spelling doaj-art-c3a3a28e3ca547ff96a5f3d031247e552025-08-20T03:33:31ZfasTabriz University of Medical Sciencesمجله پزشکی دانشگاه علوم پزشکی تبریز2783-20312783-204X2025-06-0147212414310.34172/mj.025.33830mj-33830Effects of vitamin A supplementation on visual function in healthy adults: A systematic reviewKavous Shahsavarinia0Ali MostafaeiNooshin Milanchian1Leila Roshangar2Parastu Fallahi3Moloud Balafar4Robab Mehdipour5Fereshteh Farhadi6Hassan Soleimanpour7Nasim Hajipoor8Reza Mohammadi9Hanieh Salehi-Pourmehr10Research Center for Evidence-based Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, IranDepartment of Internal Medicine, Faculty of Medicine, Tabriz Medical Sciences, Islamic Azad University, Tabriz, IranDepartment of Anatomical Sciences, Tabriz University of Medical Sciences, Tabriz, IranEmergency and Trauma Care Research Center, Tabriz University of Medical Sciences, Tabriz, IranEmergency and Trauma Care Research Center, Tabriz University of Medical Sciences, Tabriz, IranResearch Center for Evidence-based Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, IranResearch Center for Evidence-based Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, IranEmergency and Trauma Care Research Center, Tabriz University of Medical Sciences, Tabriz, IranEmergency and Trauma Care Research Center, Tabriz University of Medical Sciences, Tabriz, IranStudent Research Committee, Arak University of Medical Sciences, Arak, IranResearch Center for Evidence-based Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, IranBackground. Vitamin A plays an important role in various bodily functions, including vision. This systematic review aimed to synthesize the available evidence on the effects of vitamin A supplementation on visual function in healthy adults. Methods. A comprehensive search of electronic databases was conducted to identify randomized controlled trials investigating the effects of vitamin A supplementation on visual function in healthy adults. The methodological quality of the included studies was assessed using the Cochrane Collaboration tool. Data extraction and analysis were performed to determine the overall effect of vitamin A supplementation on visual outcomes. Two reviewers independently assessed the studies for biases, with disagreements resolved by a third reviewer. The quality of the articles was evaluated in accordance with existing standards, with any disagreements resolved through discussion or referral. Results. A search of 12945 articles from databases led to 276 full-text articles being evaluated, resulting in 17 studies. These studies examined the effects of lutein and zeaxanthin supplementation on macular pigment optical density (MPOD) and visual function. Results showed a positive correlation between MPOD and temporal contrast sensitivity function, with both improving after supplementation. However, a study by Bartlett did not find significant improvements in visual function. Most studies showed positive effects on MPOD and visual function, but the clinical significance and optimal dosage and duration remain unclear. Most studies had medium to high quality evidence. Conclusion. Vitamin A, Lutein, and zeaxanthin supplementation may improve visual function, but optimal dosage, duration, and carotenoid combination are not yet established. Long-term safety and efficacy require further investigation, including standardized assessments, longer follow-ups, diverse populations, and mechanistic studies. Practical Implications. While current research indicates that supplementing with lutein and zeaxanthin may offer benefits like improved contrast sensitivity and macular pigment density, the inconsistent findings highlight that we don't yet have a clear understanding of who will benefit most, the ideal dosage, or how long supplementation is effective for healthy adults. Therefore, widespread recommendations for these supplements to enhance vision in the general healthy population cannot be made at this time, and individuals should consult with healthcare professionals before starting any supplementation.https://mj.tbzmed.ac.ir/PDF/mj-47-124.pdfcarotenoidvitamin avisionsystematic review
spellingShingle Kavous Shahsavarinia
Ali Mostafaei
Nooshin Milanchian
Leila Roshangar
Parastu Fallahi
Moloud Balafar
Robab Mehdipour
Fereshteh Farhadi
Hassan Soleimanpour
Nasim Hajipoor
Reza Mohammadi
Hanieh Salehi-Pourmehr
Effects of vitamin A supplementation on visual function in healthy adults: A systematic review
مجله پزشکی دانشگاه علوم پزشکی تبریز
carotenoid
vitamin a
vision
systematic review
title Effects of vitamin A supplementation on visual function in healthy adults: A systematic review
title_full Effects of vitamin A supplementation on visual function in healthy adults: A systematic review
title_fullStr Effects of vitamin A supplementation on visual function in healthy adults: A systematic review
title_full_unstemmed Effects of vitamin A supplementation on visual function in healthy adults: A systematic review
title_short Effects of vitamin A supplementation on visual function in healthy adults: A systematic review
title_sort effects of vitamin a supplementation on visual function in healthy adults a systematic review
topic carotenoid
vitamin a
vision
systematic review
url https://mj.tbzmed.ac.ir/PDF/mj-47-124.pdf
work_keys_str_mv AT kavousshahsavarinia effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview
AT alimostafaei effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview
AT nooshinmilanchian effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview
AT leilaroshangar effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview
AT parastufallahi effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview
AT moloudbalafar effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview
AT robabmehdipour effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview
AT fereshtehfarhadi effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview
AT hassansoleimanpour effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview
AT nasimhajipoor effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview
AT rezamohammadi effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview
AT haniehsalehipourmehr effectsofvitaminasupplementationonvisualfunctioninhealthyadultsasystematicreview