Influence of Vitamin A supplementation on inflammatory biomarkers in adults: a systematic review and meta-analysis of randomized clinical trials

Abstract

Vitamin A is an anti-oxidant which has been presumed to act as an anti-infective vitamin in many studies. This study aimed to evaluate the association between vitamin A supplementation and c-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6) levels in randomized control trials (RCTs) studies on adults. A systematic search was performed on databases including PUBMED, SCOPUS, and the Cochrane library. The studies included were considered for data extraction and subsequently assessed for effect. Weighted mean differences (WMD) and 95% confidence intervals (CIs) were evaluated. Among 13,219 articles 13 studies were included for analysis of CRP and TNF-α, as well as 9 studies included for IL-6 in quality and quantity. The pooled WMD analysis of CRP demonstrated that vitamin A supplementation significantly increased CRP concentration with (WMD: 0.84 mg/L; 95% CI 0.29–1.39, I2 = 0.96.2% and p value < 0.003). However, there was no significant correlation between vitamin A supplementation and lower plasma TNF-α (p < 0.45)). Subgroup analysis by dosage demonstrate significant association between vitamin A supplementation and IL-6 in dosage with 50,000 with (WMD: − 1.53 mg/L; 95% CI − 2.36 to − 0.71, p value < 0.00001) as well as a negative significant association was seen at 44 weeks of supplementation with 50,000 IU/day retinyl palmitate and TNF-a in chronic hepatitis B conditions with (− 0.94 (− 1.19, − 0.69) p < 0.0001). The result of this study demonstrates that supplementation of vitamin A at low and high dosages for short and long durations increases the CRP plasma concentrations on adults and vitamin A supplementation decreases the TNF-α concentrations in chronic hepatitis B on adults. Therefore, there is an inverse association between vitamin A supplementation and plasma and fecal IL-6 concentrations in many infection conditions.

Causal effects of genetically vitamins and sepsis risk: a two-sample Mendelian randomization study

“…Vitamin A, K and B vitamins tend to have no direct association with sepsis. Vitamin A is an antioxidant with anti-infection and anti-inflammatory effects and is associated with many inflammatory markers [ 38 ]. Vitamin A deficiency in sepsis patients may be triggered by increased metabolic demands and an increase in vitamin A and retinol-binding protein (RBP) excretion in the urine during severe infection [ 39 ].…”

Novel Therapeutic Hybrid Systems Using Hydrogels and Nanotechnology: A Focus on Nanoemulgels for the Treatment of Skin Diseases

“…Retinyl palmitate (RT), a derivate of vitamin A, has shown potential for skin rejuvenation and the treatment of various dermatological conditions, such as acne, psoriasis, ichthyosis, wrinkles, dark spots, and skin aging [251][252][253]. This molecule has the capability of exfoliating the surface layer of the skin and speeding up cell turnover, increasing skin moisture, and decreasing skin wrinkles, resulting in the skin looking fresher, smoother, and younger, and also acting as an antioxidant when applied topically, preventing tissue atrophy, and having anti-inflammatory effects [254][255][256]. Nevertheless, in addition to its good properties, RT also has side effects, such as skin irritation, redness, excessive peeling and dryness, being toxic in higher concentrations, while also being a lipophilic compound, with poor aqueous solubility, and limited skin permeation, which all hinder its therapeutic efficacy [257][258][259].…”

Vitamin A: A Key Inhibitor of Adipocyte Differentiation

“…Evidence suggested that long-term low grade inflammatory basis led to obesity and associated co-morbidities [ 99 , 100 ]. However, low and high dosage administration of vitamin A decrease TNF- α and IL6 on obese adults [ 101 ]; therefore, reducing insulin resistance, and improving energy expenditure [ 102 ].…”