Vitamin A deficiency and xerophtalmia

S, Diniz Ada; Lm, Santos

doi:10.2223/jped.169

Cited by 14 publications

(9 citation statements)

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“…However, we can not omit to discuss other putative effects of VAD. For instance, it is known VAD affects the retina (night blindness), the conjunctiva (conjunctival xerosis, with or without Bitot spots), and the cornea (corneal xerosis) (Diniz Ada and Santos, 2000; McBain et al, 2007). The diurnal changes in environmental illumination are conveyed from the retina to the brain to entrain circadian rhythms throughout the body.…”

Section: Discussionmentioning

confidence: 99%

Daily patterns of clock and cognition‐related factors are modified in the hippocampus of vitamin A‐deficient rats

et al. 2012

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The circadian expression of clock and clock-controlled cognition-related genes in the hippocampus would be essential to achieve an optimal daily cognitive performance. There is some evidence that retinoid nuclear receptors (RARs and RXRs) can regulate circadian gene expression in different tissues. In this study, Holtzman male rats from control and vitamin A-deficient groups were sacrificed throughout a 24-h period and hippocampus samples were isolated every 4 or 5 h. RARα and RXRβ expression level was quantified and daily expression patterns of clock BMAL1, PER1, RORα and REVERB genes, RORα and REVERB proteins, as well as temporal expression of cognition-related RC3 and BDNF genes were determined in the hippocampus of the two groups of rats. Our results show significant daily variations of BMAL1, PER1, RORα and REVERB genes, RORα and REVERB proteins and, consequently, daily oscillating expression of RC3 and BDNF genes in the rat hippocampus. Vitamin A deficiency reduced RXRβ mRNA level as well as the amplitude of PER1, REVERB gene and REVERB protein rhythms, and phase-shifted the daily peaks of BMAL1 and RORα mRNA, RORα protein and RC3 and BDNF mRNA levels. Thus, nutritional factors, such as vitamin A and its derivatives the retinoids, might modulate daily patterns of BDNF and RC3 expression in the hippocampus and they could be essential to maintain an optimal daily performance at molecular level in this learning-and-memory-related brain area.

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Section: Discussionmentioning

confidence: 99%

Daily patterns of clock and cognition‐related factors are modified in the hippocampus of vitamin A‐deficient rats

et al. 2012

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“…The presence of one of the symptoms and clinical signs of xerophthalmia, i.e., night blindness and bitot's spot [11] with or without conjunctival xerosis, corneal xerosis with/without keratomalacia, and corneal scar bilaterally with the previous history of night blindness [11, 48].…”

Section: Methodsmentioning

confidence: 99%

Xerophthalmia and Its Associated Factors among School-Age Children in Amba Giorgis Town, Northwest Ethiopia, 2018

Belete

Fenta

Hussen

2019

Journal of Ophthalmology

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Introduction Xerophthalmia is a general term applied to all the ocular manifestations from night blindness through complete corneal destruction (keratomalacia) due to vitamin A deficiency. Xerophthalmia is the main contributing factors for childhood blindness in developing countries. However, there is limited evidence that can implicate the current situation. This study aimed to determine the magnitude of xerophthalmia and associated factors among school-age children in Northwest Ethiopia. Methods A community-based cross-sectional study was conducted on 490 children, age range of 6 to 12 years. The study participants were selected through systematic random sampling method. Data were collected using a pretested structured questionnaire and ophthalmic examination with different ophthalmic instruments. The analyzed result was summarized and presented using descriptive statistics. Binary logistic regression was used to determine the factors associated with xerophthalmia. Variables with a p value of <0.05 in the multivariable logistic regression analysis were considered as statistically significant. Results A total of 484 study participants with a response rate of 98.8 were involved in this study, and their median age was 8 years with IQR of 4 years. The prevalence of xerophthalmia was 8.26% (95% CI: 5.8, 10.7). Family income less than 1000 Ethiopian birr (AOR = 4.65, 95% CI: 1.31, 16.4), presence of febrile illness (AOR = 2.8, 95% CI: 1.49, 6.11), poor consumption of fruits and vegetables (AOR = 3.18, 95% CI: 1.30, 7.80), and nonimmunized status (AOR = 3.43, 95% CI: 1.49, 7.89) were significantly associated with xerophthalmia. Conclusions and recommendations The prevalence of xerophthalmia was high as compared to the World Health Organization criteria for public health significance. Factors identified for xerophthalmia in this study are low income, the poor dietary practice of fruits and vegetables, and the presence of febrile illness and not immunized. Hence, it is a public problem that needs attention.

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“…O estado nutricional de vitamina A existe num continuum que vai desde a deficiência clínica à toxicidade (Diniz & Santos, 2000). Até o presente, nenhum método isolado é suficientemente capaz de identificar o status de vitamina A.…”

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