Ruth Schwartz, professor emerita in Cornell's Division of Nutritional Sciences, died Sept. 19 as the result of a motor vehicle accident. She was 87.

Schwartz's research focused on the relationships between dietary magnesium and protein, especially the measurement of mineral absorption, bioavailability and utilization in animals and humans using in vitro techniques as well as stable isotopes. She developed methods that used stable isotopes to study magnesium absorption, and she studied the relationships among iron and aluminum absorption and dietary factors.

Schwartz was also interested in looking at the magnesium requirements of the elderly to determine whether they have greater dietary requirements or whether they absorb the mineral differently than younger people.

In some of her last research she studied the relationship of bone density to dietary calcium and protein, as observed in a population of Chinese women. She analyzed dietary intake, bone density and the content of physiological fluids in order to identify how diet affects bone metabolism.

Her work was published in the Journal of Nutrition, American Journal of Clinical Nutrition, Analytical Chemistry, Journal of Micronutrient Analysis, and Biological Trace Element Research.

Schwartz was born Oct. 9, 1924, in Berlin, Germany, to parents who were from Russia and Poland. In 1939, at age 14, she was sent to London under the "Kindertransport," a rescue mission that took place nine months prior to the outbreak of World War II. This was the last Schwartz saw of her parents, who died in World War II.

She went on to earn a B.S. in chemistry and physiology in 1947 and a Ph.D. in nutritional biochemistry in 1959 from London University, England. After working as a biochemist for the United Kingdom's Medical Research Council 1950-57 and a lecturer at the London School of Hygiene and Tropical Medicine 1960-63, she became an assistant professor, in 1965, and later an associate professor at the University of Connecticut. In 1970, she joined the Cornell faculty as an associate professor of nutritional sciences in the College of Human Ecology and was promoted to professor in 1979. She retired in 1993 and became an emerita professor in 1998.

She is survived by a brother, extended family and her longtime companion, Seymour Smidt, professor emeritus of finance, who was injured in the car accident.

Funeral services were held Sept. 24 in Ithaca and a burial followed at Lakeview Cemetery, Ithaca.