Abstract
Since previous studies suggest that people with cystic fibrosis and pancreatic insufficiency tend to be deficient in fat-soluble vitamins like vitamin A, the study endeavored to establish whether vitamin A intake could lead to elevation of serum retinol levels in the blood. Serum retinol levels were measured in 78 participants who were between 8 to 25 years. Assessments were done using high-performance liquid chromatography. These were subsequently compared to NHANES data obtained from participants having similar ages. Measurements of vitamin A intake, anthropometry, and FVE1 were undertaken. Assessment of these measurements was then done. Fifty-eight percent of the participants did not feature in the NHANES reference range. Intake of vitamin A was above the recommended dietary allowance of 600+431% (Maqbool et al 2008). There was no correlation between serum retinol and vitamin A intake, age of the participants and their sexes. However, there was an inverse correlation between serum retinol with weight and height of z-scores in participants with Cystic Fibrosis. The study, therefore, arrived at a conclusion that intake of vitamin A and serum level was high in participants with CF and PI.
Introduction
The study was initiated courtesy of a previous study whose findings showed high retinal concentration in individuals with cystic fibrosis and pancreatic insufficiency which was contrary to the belief that these conditions make such people fat-soluble vitamin malabsorption. The study intended to state vitamin A status and to approve or disapprove the initial research findings with participants having a broader age range.
Materials and Methods
Participants were both children and young adults whose ages ranged between 8 to 25 years. They both exhibited CF and PI conditions. They were picked from pediatric and CF facilities. An inclusion criterion was majorly anchored on the diagnosis of CF and PI using standard methods. Participants with other major medical conditions were never allowed to take part in the study likewise to those who had less than 40% FEV1 (Maqbool et al 2008). After the collection of serum, retinol analysis was done by HPLC. The levels were then compared with those of NHANES’ ranges from age-equivalent white participants. Heights and weights were measured using a stadiometer and a digital scale. Z-scores were calculated. Pulmonary function was worked out using standard methods. Dietary intake for 3-day weighed food was determined by research technicians. Vitamin A intake in participants with cystic fibrosis was corroborated. Test for normality and skewness was conducted for all variables. Group comparisons were tested with the help of either Student’s T-test or the Wilcoxon rank-sum test. Presentation of data was done in terms of mean+ or –standard deviation, the calculated median values, and range. In testing significant variation between variables, spearman rank correlations were employed.
Results
The 78 participants who took part in the study all had serum retinol, anthropometry, and FEV1. Nine percent of the participants took part in the current research and the pre-adolescent study. There was dietary intake data for 53 participants. Subjects who had no dietary data had lower percentages of FEV relative to those with complete dietary data. 42% of the participants had serum retinol whereas 58% of them had concentrations above NHANES’ reference range. No participant with CF and PI possessed serum retinol below the lower reference range. Vitamin A that was derived from food and supplement was 608±431% RDA. A whopping 67% was derived from supplements.
Discussion
With the help of NHANES reference data, it was found that 58% of participants with CF and PI had high levels of serum retinol concentrations. These findings have raised concerns as to the possibility of the risk of vitamin A toxicity in the population with cystic fibrosis. Vitamin A helps in maintaining cell integrity, encourages cell growth, and enhances the operation of the immune system. Preformed retinoids and pro-vitamin A carotenoids serve immune functions. A major limitation to the study was that it involved the use of cross-sectional design and that analysis of vitamin A in people with cystic fibrosis was secondary in their bone health.
Conclusion
The study, therefore, arrived at a conclusion that intake of vitamin A and serum level was high in participants with CF and PI.
Reference
Maqbool, A., et al. (2008). Vitamin A intake and elevated serum retinol levels in children and young adults with cystic fibrosis. Journal of Cystic Fibrosis, 7, 137–141.