Thinking about what you said, from compassionate standpoint only, then ideally of course it would be okay to drink a glass of milk a day and eat eggs!
But unfortunately the world of farming and consumerism doesn't work that way.
If you had a cow who was treated very well, and lived in a field with lots of grass, and good shelter and who was respected...and she had a calf and came into milk, then (if she allowed you to) taking a glass of milk every day from her wouldn't make a great deal of harm or difference. She would be content and healthy. Her calf would still be well-fed.
Now I actually knew a man who did exactly that. He loved his cows, and treated them well indeed. He lived in a bothy in the same field as his cows. He took a little milk each day, enough for his own needs, and this caused no harm to the cows or calves.
He was a Krishna follower too.
But that isn't how dairy cows or their offspring are treated in the 'real world' of dairy farming. Even organic dairy farmers are more or less forced to treat their herd and the offspring in a similar way.
https://www.peta.org/issues/animals-...airy-industry/
Have you ever lived near a farm -even a fairly 'kind' farm, where the animals have access to fresh air and grass and proper exercise? Have you ever heard those plaintive endless calls in the night of a mother to her lost young ones, taken away (and if they happened to be male -killed)? I have because I live a quarter mile away from a dairy farm. And those hollow calls will go on until I literally hear the cow go hoarse.
Eggs....there's another one. Absolutely....what's the harm in taking a couple of unfertilised eggs for your breakfast, from hens who are happy, cared for, live mostly outdoors, with good shelter and protection against predators? Now there are cases of hens becoming emotionally attached to their eggs, and then you have a 'broody hen'. They should be respected, and allowed to work out their attachment in their own time. It may be hormonal, but they still deserve respect. But many hens will dump their eggs which will go bad -so what's the harm in scooping some up? No harm.
But again -that's not the way the egg industry works either. Even "free range" eggs aren't always telling a good story about what happens to the hens. And certainly "Barn eggs" come from hens who have the most weird and sad life, usually of one year long only -then horrendous slaughter. And that's even before we get to caged hens and egg production! (do I need to spell that out?)
There is also a chicken farm just down my lane where barn eggs are produced, so I know what happens. Unmarked trucks -16 wheelers -come slowly down the lane in the dead of night when the barns are 'cleared'. I feel there is too much shame or something for them to come in the daytime, because they always come at 2-3am.
I always say a prayer for those animal souls because I know what happens to them. It is not just a quick death either.
And of course the baby male birds are put alive into grinders as they cannot produce eggs!
Okay, if you know someone who loves hens and keeps them on their land or garden and all is well then eating a few eggs (I feel) is no harm done. But commercial eggs have a terrible story behind them.
Yes we can't be perfect. And some people cannot handle a totally vegan diet. I appreciate that. But that just means compromises have to be made one way or another. It's always good though if extra work can be put in to try to find a genuine humane supplier or neighbour who believes in true animal welfare.
For anyone who wants to be vegan but who is worried about B12:
https://www.vegansociety.com/resourc...ts/vitamin-b12
There are vegan supplements also for Omega 3 and other nutrients. Research is helpful if you are committed. It is not too hard to research what is needed.
And "doing the maths" about the cost of such supplements usually works out at not much more -or even the same -as the cost of animal food products in the diet weekly.