Effect of intramuscular vitamin A injection on plasma levels of vitamin A and retinol-binding protein in malnourished children

Abstract

1. Serum levels of retinol-binding protein (RBP), total vitamin A and retinyl ester were measured in twenty-four malnourished children with corneal lesions and nine normal children.2. Initially, the RBP and vitamin A levels were significantly lower in malnourished children than in normal children.3. After intramuscular injection of 30000 pg of aqueous vitamin A, serum levels of total vitamin A were increased significantly at 24 h and tended to fall within 5 d of treatment in both groups.4. Before treatment, retinyl ester accounted for less than 10% of the vitamin in circulation. After vitamin A injection, it increased to 30%, a level much lower than that reported in patients with hypervitaminosis A.5. There was no significant difference between the two groups of children and none of them showed clinical signs of toxicity. These observations indicate that administration of massive doses of vitamin A over a short period will not produce toxic effects even in malnourished children.

A comparison of three vitamin a dosing regimens in extremely-low-birth-weight infants

“…Marked variability in retinol concentrations were seen in the higher dose group, which may be due to differences in bioavailability or retinol half-life in individual neonates, as has been noted in adults and older children. [18][19][20] In view of the lack of improvement in biochemical measures and the possibility of toxicity, the higher dose regimen cannot be recommended, based on our findings. Because smaller infants have a higher incidence of lung disease and corresponding lower reserves 12 and enteral intakes of vitamin A, 2 doses of vitamin A were not adjusted for body weight in this study nor in the NICHD trial.…”

“…In adults and older children, retinol and retinyl palmitate concentrations after intramuscular administration normally peak 48 hours later, persist for about 2 days, and decline within 5 days. [18][19][20] Consequently, the retinol concentrations in the higher dose and standard regimens may be higher as compared with those in the once-per-week regimen, as the retinol measurement was done earlier. The explanation is likely, because RDR and RBP were not lower in the once-per-week regimen as compared with the other two regimens, indicating that vitamin A stores may have been similar in magnitude in all three regimens.…”

“…Retinol concentrations on study day 1 were not associated with subsequent BPD/death (13 [11-21] µg/dL in survivors without BPD vs 14.5 [7][8][9][10][11][12][13][14][15][16][17][18][19][20] µg/dL in infants with BPD/death [median value; 25%-75% in parentheses; P = .71]). To evaluate if group assignment or retinol levels were associated with BPD/death, a multiple logistic regression analysis was performed with BPD/death as the dependent variable and birth weight, gestational age, sex, race, mechanical ventilation at 24 hours, FIO 2 at 24 hours, mean airway pressure (MAP) at 24 hours, serum retinol on study day 1, and group assignment as independent variables.…”

Vitamin A supplementation downregulates ADH1C and ALDH1A1 mRNA expression in weaned beef calves

“…Similarly, supplying 100 IU/kg BW of vitamin A to Shal sheep aged 4 to 6 months significantly increased plasma vitamin A compared to receiving 50 IU/kg BW ( Asadian and Mezes, 1996 ). It suggested that although large amounts of vitamin A injection in one dose led to a rapid increase in blood vitamin A concentration in a short time, maintaining blood vitamin A levels stably at a high level requires consistent vitamin A administration orally ( Peng et al., 2020a ; Reddy and Mohanram, 1981 ). Also, we found that serum vitamin A concentration was significantly lower in TC calves than in TT calves after vitamin A supplementation.…”