Effect of Vitamin A Intake on Some Biochemical and Physiological Changes in Swine

• Published in: The Journal of nutrition Vol. 76; no. 4; pp. 325 - 332
• Main Authors: Nelson, Eldon C., Dehority, Burk A., Teague, Howard S., Sanger, Vance L., Pounden, William D.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.1962
• Subjects: Animals; Diet; Humans; Nutrition Assessment; Nutritional Status; Old Medline; Swine; Vitamin A; VITAMIN A/nutrition and diet; SWINE/nutrition and diet
• ISSN: 0022-3166
• DOI: 10.1093/jn/76.4.325

Thirteen purebred Yorkshire pigs were weaned at three weeks of age and fed a purified vitamin A-deficient diet ad libitum until blood plasma vitamin A concentrations were less than 7 µg/100 ml. Cerebrospinal fluid pressures were then measured and the pigs were assigned to either 2, 4, 8 or 16 µg of vitamin A per pound of live weight per day. The basal diet was then fed at the rate of 4.0% of each pigs body weight and increased 0.3 pound per pig at the end of each week. At the end of 11 weeks, terminal cerebrospinal fluid pressures and plasma vitamin A concentrations were measured, the animals were killed and the concentrations of some constituents of blood serum, cerebrospinal fluid and aqueous humor determined. In addition, a histological examination was made of various tissues including the eye and the parotid salivary gland and duct. Growth rate was not affected adversely by vitamin A intake. Cerebrospinal fluid pressure increased with decreased blood plasma vitamin A concentration and vitamin A intake. Blood plasma vitamin A, liver vitamin A and serum potassium increased with vitamin A intake. Histological examinations indicated there were no consistent changes relative to vitamin A intake. The minimal vitamin A requirement for the pigs under the experimental conditions of this study necessary to produce normal plasma vitamin A, some liver storage and low CSF pressure appeared to be between 8 and 16 µg of vitamin A per pound of live weight per day.