Off-campus South Dakota State University users: To download campus access theses, please use the following link to log into our proxy server with your South Dakota State University ID and password.

Non-South Dakota State University users: Please talk to your librarian about requesting this thesis through interlibrary loan.

Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)



First Advisor

Ivan S. Palmer


Early investigators described selenium as being highly toxic and possibly carcinogenic as reviewed by Moxon(1), and Rosenfeld and Beath(2). However in 1957 evidence was presented indicating that selenium was an essential nutrient(3) especially in production animals, because supplementation prevented a wide array of disorders; some of these disorders have been known since the thirteenth century(1,2). In 1973, Rotruck et al(4), reported the first actual metabolic role of this trace element in mammals as an active component of the enzyme glutathione peroxidase (Gpx). Gpx is involved in the destruction of hydroperoxides, and it has been shown in most mammalian tissues including milk(5,6). Vitamin E, a fat-soluble vitamin, is a proven antioxidant by itself. It was once thought that selenium can prevent vitamin E deficiency and vice versa. Both selenium and vitamin E can give rise to toxicity and deficiency disorders. Selenium is especially important, because its concentration in food is known to increase with the increasing soil selenium content. Areas with high level of selenium that can cause toxicity have been reported in various parts of the world(2) including the western part of South Dakota, where selenosis has been reported in anima1s(1). On the other hand, selenium deficiency has been reported in areas such as Nepal, New Zealand(7), and some areas of China(8) where selenium is very low in the soil. Human breast milk is a major source of nutrition for infants. Generally it is well known that human milk is nutritionally adequate, and that the nursing process is advantageous to the infant emotionally (9,10). Much work has been done to determine selenium and vitamin E concentrations in human milk in different geographic locations to investigate the selenium and vitamin E status of infants in these areas(9,11,12,13,14,15). Another nutritional source for infants is the cow's milk-based infant formula. Most studies have shown less selenium and vitamin E in infant formula than in human breast milk(11,13,14,16). A question has been raised "should selenium be added to infant formula, and if so, how much?"(11,13,14). The main purpose of this study is to determine selenium content of human breast milk in South Dakota (an example of a high selenium area), and to compare the results with those reported for other areas. Special emphasis will be placed on the effect of geographic distribution and the stage of milk production on selenium content. The data will provide baseline in formation necessary to establish guidelines for establishing suitable supplementation levels in infant formulas. Also, this study included determining vitamin E in the same samples in order to provide information on vitamin E in human milk.

Library of Congress Subject Headings

Vitamin E
Breast milk -- Composition -- South Dakota
Breast milk -- Health aspects -- South Dakota



Number of Pages



South Dakota State University