The closest related to food was stain removal from plastic containers. The rest are polishing or cleaning related. Which makes sense – like vinegar, citrus is mildly acidic, organic and non-toxic. There’ve been studies that suggest vinegar is better than chlorine for cleaning.
There is a “low” dose of vitamin K in lemons. But lemons are not the sort of thing many are going to over-consume 😉 I don’t have details, but I suspect the vitamin K is in the zest, as with most citrus fruit.