Vitamin E: Not only a single stereoisomer.

The recent publication by Azzi and colleagues puts forth the argument that only RRR-α-tocopherol should be considered as vitamin E from a physiological point of view. They base their argument primarily on the assertion that only this form has been used to treat stark vitamin E deficiency in humans (known as AVED, or Ataxia with Vitamin E Deficiency). Azzi et al. also argue that other chemically similar molecules, such as tocopherols other than α-tocopherol and tocotrienols do not provide vitamin E activity. Azzi and colleagues are correct on this second point. An investigation into the biological activities of vitamin E, and the mechanisms behind these activities, confirms that physiological vitamin E activity is limited to certain α-tocopherol forms. However, it is also clear that these activities are not restricted only to the RRR-form but include other 2R-forms as well. Indeed, the α-tocopherol transfer protein (α-TTP), which is critical to mediate vitamin E trafficking and biological activity, and genetic defects of which lead to vitamin E deficiency, binds well to all 2R-forms of α-tocopherol. Furthermore, both RRR-α-tocopherol and the other 2R-forms are maintained in human plasma and distributed to tissues and organs, whereas the 2S-stereoisomers are excreted quickly. As such, in recent years the definition of vitamin E including both 2R- and RRR-α-tocopherol has gained both broad scientific and regulatory acceptance. Consistent with this understanding, we provide evidence that AVED has indeed been treated successfully with forms in addition to RRR-α-tocopherol, again arguing against the restriction of the definition to RRR-α-tocopherol only. Finally, we provide evidence against any safety concerns utilizing the currently accepted definition of vitamin E.

Suplementacion con vitaminas liposolubles en pacientes con fibrosis quistica: ¿es suficiente con Aquadek’s®? / Fat-soluble vitamins supplementation in patients with cystic fibrosis: is enough Aquadek’s®?

Introducción y objetivo: Conocer si la suplementación un nuevo polivitamínico (Aquadek’s®) durante 12 meses es segura y eficaz en pacientes con Fibrosis Quística (FQ). Material y Métodos: Estudio prospectivo, longitudinal y no controlado en pacientes con FQ insuficientes pancreáticos, clínicamente estables, que recibieron suplementación con Aquadek’s® (2 comprimidos masticables) durante 12 meses en lugar de su suplementación habitual. Se evaluaron niveles séricos de retinol, betacarotenos, 25 OH vitamina D y α-tocoferol un año antes, al inicio y tras un año de tratamiento. Análisis estadístico: Pruebas t para datos pareados. Resultados: Se incluyeron 28 pacientes entre 6 y 39 años (mediana 18,5 años). La suplementación con Aquadek’s® supuso un incremento en la dosis de vitaminas A y una disminución del número de comprimidos administrados. Al inicio, un 89% presentaban algún tipo de dé- ficit vitamínico: (61% pro-Vitamina A y 54% vitamina D). Tras un año, se produjo un incremento de los niveles de betacarotenos: 160 mcg/l (IC 95% 98-222) (p<0,001) y disminuyó el porcentaje de pacientes con deficiencia de dicha pro-vitamina un 46% (IC 95% 22-64) (p<0,001). Vitamina D aumentaron un 18% (IC 95% 2-32) (p=0,025). En ningún caso los niveles séricos sobrepasaron los límites indicativos de toxicidad. Conclusiones: La suplementación con Aquadek’s® en el formato de comprimidos masticables es segura y eficaz para mantener el estatus de las vitaminas A y E en pacientes con FQ mayores de 6 años, aunque es insuficiente para mantener niveles séricos de 25 OH vitamina D dentro de las recomendaciones para esta enfermedad (AU)

Introduction and objective: Evaluate the safety and efficacy of a novel polyvitaminic (Aquadek’s®) in patients with Cystic Fibrosis (CF). Material and Methods: Prospective, longitudinal and non-randomized study. CF patients with pancreatic insufficiency and clinically stable were given Aquadek’s® (two chewable tablets) daily for 12 months. Serum levels of retinol, beta-carotene, 25 OH vitamin D and α-tocopherol were evaluated twelve months before, at baseline and 12 months after. Statistical analysis: paired ttests. Results: 28 patients aged 6 to 39 years (median 18.5 years) were included. Aquadek’s® supplementation led to an increase in vitamin A dose and a decrease in the number of tablets administered. At baseline, 89% had at least one vitamin deficiency (61% pro-Vitamin A and 54% vitamin D). After one year, serum beta-carotene levels were increases 160 (95% CI 98-222) mcg/l (p<0,001) and decreased the percentage of patients with pro-vitamin A deficiency 46% (95% CI 22-64) (p<0,001). The proportion of patients with vitamin D insufficiency increased 18% (95% CI 2-32) (p =0.025). In any case serum levels exceeded the upper limits used to assess the risk of toxicity. Conclusions: Two daily Aquadek’s® chewable tablets are safe and effective for maintaining vitamin A and E status of CF patients older than 6 years, although it is insufficient to normalize serum 25OHvitaminD according to the current recommendations for this disease (AU)

Efecto de la suplementación de vitamina E en el rendimiento de una prueba incremental de consumo máximo de oxígeno en ratas wistar / Effect of vitamin E supplemantation on the performance of an incremental maximal oxigen uptake test in wistar rats

Diversas investigaciones han investigado el efecto de la suplementación de vitamina E en diversos marcadores de estrés oxidativo y en el rendimiento de diversas pruebas de resistencia, pero nunca en una prueba incremental hasta alcanzar el consumo de oxígeno máximo. Este trabajo pretende investigar el efecto de la toma de vitamina E en el rendimiento de una prueba incremental hasta alcanzar el consumo de oxígeno máximo en ratas. Se analizaron 2 grupos de ratas (G1: 190.8±1.83 gr; G2:198.0±0.86 gr), ambos realizaron una prueba incremental máxima en tapiz rodante (5’ a 25 cm/s mas aumentos de 3cm/s cada minuto hasta la extenuación). Dos horas antes de la prueba se administró al G1 un placebo (agua bidestilada) y alG2 una dosis de 1000UI/kg de peso de vitamina E, mediante una cánula endotraqueal. El G2 presentó unos valores deVO2max, VCO2max, VCO2relativo y RQ significativamente superiores (p<0.05) a los del G1. No se observaron diferencias significativas en las variables de VO2 relativo (G1: 87.1±7.61 vsG2: 91.0±3.55 ml/kg/min), tiempo final (G1: 1231.4±297.6 s vs G2: 1268.1±115.5 s) y velocidad final (G1: 76.6±14.91 cm/s vs G2: 78.3±5.89 cm/s). Estos datos muestran que la suplementación con una dosis de 1000 UI/kg peso de vitamina E no aumenta el rendimiento de ratas wistar al realizar una prueba incremental máxima hasta alcanzar el consumo de oxígeno máximo en tapiz rodante (AU)

Several studies have investigated the effect of vitamin E supplementation in various markers of oxidative stress and performance in different endurance exercises, but never in an incremental test to reach the maximum oxygen uptake. This work aims to investigate the effect of vitamin E supplementation on the performance of an incremental test to reach the maximum oxygen uptake in wistar rats. We analyzed two groups of wistar rats (G1: 190.8 g SEM 13.4, G2: 198.0 1.49 g SEM), both performed a maximum incremental test on a treadmill (5 ‘ to 25 cm/ s and increases of 3 cm/s every minute until exhaustion). Two hours before maximum incremental test G1 was administered a placebo (bi distilled water) and G2 was administered a dose of 1000UI/kg weight of vitamin E using an endotracheal tube.VO2max, VCO2max, relative VCO2 and RQ were significantly higher (p <0.05) in G2 when compared to G1. No significant differences were found for relative VO2 (G1: 87.14±7.61 vs G2: 91.00±3.55 ml/kg/min), final time (G1: 1231.40±297.63s vs G2: 1268.10±115.47 s) and final speed (G1: 76.60±14.91cm/s vs G2: 78.30±5.89 cm/s) between the two experimental groups. These data show that supplementation with a dose of1000 IU / kg vitamin E does not increase the performance of Wistar rats in an incremental test to reach maximum oxygen uptake (AU)