Could pernicious anemia, a disease caused by a vitamin B12 deficiency, have explained the many strange behaviors of Mary Todd Lincoln?

She was not exactly a model first lady. Historians have had a field day describing her violent temper, wild shopping sprees (she owned 300 pairs of kid gloves), depressed moods and all-consuming fears of burglars, storms and poverty. Late in life, at her son’s urging, she was committed to a mental hospital for several months.

Plenty of theories, none proven, have been floated. She was bipolar. She had syphilis or that well known cause of feminine madness, menstrual trouble. She was spoiled and narcissistic. She never recovered from a road accident in which her head hit a rock. She lost her mind grieving the deaths of three of her four sons and her husband’s assassination.

The latest addition to the list of possible diagnoses comes from Dr. John G. Sotos, a cardiologist, technology executive at Intel and one of the medical consultants who helped dream up the mystery diseases that afflicted patients on the television show “House.”