Effect of vitamin A deficiency on the immune response in obesity

Abstract

Obesity has been associated with low-grade systemic inflammation and with micronutrient deficiencies. Obese individuals have been found to have lower vitamin A levels and lower vitamin A intake compared with normal-weight individuals. Vitamin A plays a major role in the immune function, including innate immunity, cell-mediated immunity and humoral antibody immunity. It has also been recognised recently that vitamin A has important regulatory functions. Vitamin A status has an important effect on the chronic inflammatory response. Vitamin A deficiency increases a T-helper type 1 (Th1) response, elevates levels of proinflammatory cytokines, increases the expression of leptin, resistin and uncoupling proteins (UCP) and promotes adipogenesis. The effect of vitamin A deficiency on obesity might be increasing the risk of fat deposition and also the risk of chronic inflammation associated with obesity. Supplementation with vitamin A in vitro and in animal models has been found to reduce concentrations of adipocytokines, such as leptin and resistin. In conclusion, vitamin A deficiency increases a Th1 response in the presence of obesity and thus, increases the inflammatory process involved in chronic inflammation and fat deposition. The metabolism of leptin and other adipocytokines may play a critical role in the effect of vitamin A deficiency in the inflammatory response observed in obesity.

All- trans -retinoic acid represses chemokine expression in adipocytes and adipose tissue by inhibiting NF-κB signaling

“…This discrepancy may derive from the major 337 differences between the two experimental protocols (use of vitamin A or ATRA, duration of treatment, concentrations of substances used, etc.). However, our results seem to be in line with the suspected role of vitamin A deficiency in elevated proinflammatory cytokines and T-cell activation [36,37]. …”

Zinc, Iron and Vitamins A, C and E Are Associated with Obesity, Inflammation, Lipid Profile and Insulin Resistance in Mexican School-Aged Children

“…(2003), who found that low concentrations of vitamin A in Thai adults who were overweight and obese were associated with higher weight, BMI and hip circumference [47]. In a study in women from the same rural areas in Mexico, vitamin A was positively related to measures of obesity, but only on the lowest terciles of BMI (<30 kg/m 2 ), waist circumference (<84.6 cm) and body fat (<36%) [48]. The effect of vitamin A on adipogenesis, specifically retinoic acid, appears to be dose-dependent, suggesting that the relationship between vitamin A and adiposity differs in individuals with higher BMI and body fat content [4].…”

Aldehyde Dehydrogenase 1A1: Friend or Foe to Female Metabolism?

“…Females tend to have higher SF mass and insulin sensitivity [97,101] possibly due to the adiponectin production in SF [102,103]. Recently, many comprehensive reviews have discussed the collective influence of sex hormones and retinoids in the regulation of cytokine production and secretion in various tissues, including adipose (reviewed in [97,104,105,106]). The extent of ALDH1A1’s influence can be better explained through the differences in plasma cytokine profiles of WT and Aldh1a1 −/− mice on a high-fat diet [23].…”