One way into this quantification is to consider healthcare is a matter of prevention and cure. Clearly, both are knowledge-based.
With cure, the knowledge is applied by a health provider. The knowledge stems from education (whether academic or traditional). It is easy to quantify the results of cures, but it is hard to attribute the share of knowledge in this - how much of the cure is the result of the medicine or procedure, and how much is the result of the knowledge used to create the pill, and the knowledge of which pill to apply, when, where and how? So I wouldn't try to quantify the effects of knowledge in cure.
Prevention, on the other hand, is dispensed by a range of sources, and applied by the individual. Prevention is a matter of saying, to perfectly healthy people, "If you do this, you won't get sick". It is the pure application of knowledge, and nothing else. This can often be quantified.
So I would suggest that all the people saved by prevention (including by vaccines) can be counted as people saved by knowledge. And thus "people dying for lack of knowledge" are all those who fail to apply the knowledge. For example, people who die of vaccine-preventible diseases are literally dying for the lack of knowledge. Other knowledge-preventable causes of death include obesity, indolence/lack of exercise, smoking,..., These numbers are easily available.
HIFA profile: Chris Zielinski: As a Visiting Fellow in the Centre for Global Health, Chris leads the Partnerships in Health Information (Phi) programme at the University of Winchester. Formerly an NGO, Phi supports knowledge development and brokers healthcare information exchanges of all kinds. Chris has held senior positions in publishing and knowledge management with WHO in Brazzaville, Geneva, Cairo and New Delhi, with FAO in Rome, ILO in Geneva, and UNIDO in Vienna. Chris also spent three years in London as Chief Executive of the Authors Licensing and Collecting Society. He was the founder of the ExtraMED project (Third World biomedical journals on CD-ROM), and managed the Gates Foundation-supported Health Information Resource Centres project. He served on WHO’s Ethical Review Committee, and was an originator of the African Health Observatory. Chris has been a director of the World Association of Medical Editors, UK Copyright Licensing Agency, Educational Recording Agency, and International Association of Audiovisual Writers and Directors. He has served on the boards of several NGOs and ethics groupings (information and computer ethics and bioethics). UK-based, he is also building houses in Zambia. chris AT chriszielinski.com
His publications are at www.ResearchGate.net and https://winchester.academia.edu/ChrisZielinski/ and his blogs are http://ziggytheblue.wordrpress.com and https://www.tumblr.com/blog/ziggytheblue