i.e. do vegans avoid buying food from company X because company X also makes non-vegan food
do vegans not shop at the typical grocery store because that store
Most will try to source their food from veg[etari]an shops but in practice it is difficult to avoid companies which also handle meat.
Do your research, as it’s difficult to determine who buys what, or if some vegan consumers are fine with other products they sell.
Its very difficult to avoid buying foods made by companies that do a large trade in a wide variety of food.
the easiest way to accomplish that would be to buy fresh as much as possible. Or grow some of your own.
Stand near any vegan, soon enough they will tell you all about being a vegan.
It is pretty hard to do as a lot of companies nowadays are actually ultimately owned by huge mega companies that sell toxic foods.
If you have the time and good availability, you can do your best to only support companies whose ethics you agree with. Buying local is a good way to do that.
I'm a vegan. And I do consider where I purchase foods and who profits from my business. And whenever and wherever possible I will go out of my way and spend extra money to buy products that are cruelty-free and ethically sourced.
But the interconnections severely limit what is practical and possible. I call it a ceiling. and it is not very high.
For instance, although I buy most of my produce (in the summer) at farmer's markets I still visit grocery stores all the time. Grocery stores besides selling plant foods also sell animal products. Not only that they also actively participate in things like poisoning rodents and bugs.
Although there are still quite a few family-owned ethical food manufactures, Annie's comes to mind. Something like 80% of our food comes from about 10 mega-corporations. ( I think its like 50% that comes from just 4 of those - The Big 4.)
I don't buy Gardein products. One of the reasons is that Tyson bought them. But I still buy Field Roast even though they were bought by a meat company. Many vegans don't worry about this issue cause they don't buy processed meats. Some even make their own plant milk.
I wouldn't say that the rest of us don't care. but there is hardly any alternative.
It's unlikely they buy from strictly vegan sources. Dean Dairy is the largest producer of milk in the US, but they also own a big soymilk brand. Kraft (cheese) also owns some veggie brands. Tyson (meats)bought an interest in the Beyond Meat.
It's very, very rare that a vegan would be able to do that with all the food and drink they bought.
Even if a vegan was able to buy all their food and drink from a strictly vegan shop, it's likely that a company that also produces, processes, distributes or sells non-vegan produce will be involved somewhere along the line.
Obviously I don't have any figures (I doubt anyone does) but I'd guess most vegans buy their food the same places the rest of us do.