Wills conducted research into prenatal macrocytic anaemia in India in the 1920s and 1930s, where pregnant textile workers in Bombay were suffering from the condition.
She hypothesized that the condition, which causes red blood cells to become enlarged and can be life-threatening, was related to the diets of those affected.
After feeding monkeys with the condition the popular yeasty breakfast spread Marmite, she observed that their symptoms alleviated. Later studies based on her research found that it is a lack of folic acid, which Marmite contains, that causes the condition.
Her work immediately benefited pregnant textile workers in Bombay, where she was based, and folic acid is now recommended for pregnant women everywhere.
“Remembered for her wry sense of humor, Wills enjoyed mountain climbing, cross-country skiing, and rode a bicycle to work rather than driving in a car,” Google wrote. “She devoted much of her life to traveling the world and working to ensure the health of mothers-to-be.”
She died in 1964; Friday marked 131 years since her birth.