Strict vegan, low-calorie diet administered by caregiving daughter to elderly mother--is this elder abuse?

We present a case in which a 40 year old woman, who was the primary care-giver of her 78 year-old mother, provided a strict vegan diet which caused the mother severe malnutrition. The mother was hospitalized with severe functional deterioration and, while eating a proper diet during hospitalization, gained weight and her condition improved. The case was reported to the Welfare Officer and the mother was released under the supervision of the Welfare Officer. Cases of severe malnutrition and even death of infants who were fed a strict vegan diet have been reported. This case raises some ethical and legal issues. Should a guardian or a caregiver be allowed to make decisions regarding the way of life and medical treatment of the person in his/her charge which are likely to endanger that person's health and when is it appropriate for society to intervene in individual freedom? The paper includes a review of some reported cases of child and elder abuse or neglect which illustrate these issues.