Having looked into it further there is a comment “Older antiepileptic drugs (AEDs) can adversely affect bone health by directly affecting the cells of bone formation and absorption or by secondary effects on calcium and vitamin D metabolism”. The study later reports that some of the participants had tried and failed 8 AEDs which could suggest that they are responsible for the continued adverse effects on bone health, rather than it being a direct result of the Ketogenic diet.

For speculative purposes, as the participants already had a “poor” rating does this show correlation rather than causation? Could the have a genetic predisposition to bone mineral loss etc rather than it being a direct result of the ketogenic diet? Or is there an underlying mechanism of ketosis that would directly influence the composition of bone minerals.