Influence of ascorbic acid on selenium nutrition in the chick

Area of Science:

• Nutritional Biochemistry
• Animal Nutrition
• Trace Element Metabolism

Background:

• Selenium is an essential trace element crucial for antioxidant defense, primarily through the enzyme glutathione peroxidase.
• Vitamin E and selenium often work synergistically in preventing oxidative damage in animals.
• The interaction between ascorbic acid (vitamin C) and selenium nutrition is not fully understood.

Purpose of the Study:

• To investigate the impact of dietary ascorbic acid on selenium metabolism and requirements in chicks.
• To determine if ascorbic acid influences the activity of selenium-dependent enzymes.
• To elucidate the mechanism by which ascorbic acid might affect selenium absorption.

Main Methods:

• Chick feeding trials with varying levels of dietary selenium and vitamin E.
• Measurement of glutathione peroxidase activity in plasma.
• Intestinal absorption studies using ligated duodenal loops and oral dosing.
• Analysis of ascorbic acid levels in plasma and tissues.

Main Results:

• Ascorbic acid supplementation increased plasma glutathione peroxidase activity in chicks.
• Dietary ascorbic acid appeared to lower the selenium requirement in vitamin E-deficient chicks.
• Ascorbic acid significantly promoted the intestinal absorption of selenium but did not affect vitamin E absorption.
• Ascorbic acid levels in plasma and tissues were unaffected by selenium or vitamin E deficiency.

Conclusions:

• Dietary ascorbic acid enhances selenium absorption and potentially its utilization in chicks.
• Ascorbic acid may reduce the dietary selenium requirement, particularly under conditions of vitamin E deficiency.
• The findings support the hypothesis that reduced selenium oxidation facilitates its absorption and utilization.