I'm never sure when you're joking. There's a reason why this sort of thing is called an Old Wives Tale. Here's a list of dietary improvements you can make if your red blood cell count is low:
https://www.medicalnewstoday.com/articles/319457. Milk is only helpful if it's vitamin B12 deficiency that you are experiencing. And there is no milk in Milk Stout, only
lactose (and hence no B12, unfortunately).
If it's iron that is low, here's what you should be eating:
shellfish, such as oysters, clams, and mussels
fortified cereals
oysters
spinach
chocolate with 45–69% cacao solids
chickpeas
tuna
sardines
baked potato with the skin attached
beef liver
beef
tofu
chicken liver
white beans
lentils
Good luck with finding a beer with those in!