Lucy Wills was born on May 10, 1888, in Sutton Coldfield, England. Despite women having few opportunities for education and careers until the end of the 19th century, Wills attended multiple colleges--although she wasn’t eligible to earn a college degree due to her being a woman. The London School of Medicine for Women was the first school in Britain to train women to become doctors and had links to India, including many students there, which is why Wills ended up going to India once she became a qualified medical practitioner. 

Wills became interested in studying pregnancy and in 1928 she travelled to India to study macrocytic anemia in pregnancy, which causes the red blood cells to be larger than they normally are. She discovered that though the patients were responding to crude liver extracts, they weren’t responding to “pure” liver extracts (which are chock full of vitamin B12). This led her to discover there must be another factor than just B12 deficiency.