blood spots in eggs

[polar chicks]

I am new to raising chickens and I have 4 black australorps, 4 buffs, and 2 EE, and one rooster EE. I have had blood spots or meat spots in every darker colored egg that I get. Are the black australorps prone to these blood spots???? I've read somewhere on this forum that you can give them vitamin A to help with the blood spots in the eggs but how do you give them vitamin A? I want to sell these eggs but I dont want to have so many spots in them and I've tried to candle them but I cant see inside the eggs.
Can anyone give me some advise on this problem??????? Oh yeah, today there was an actual smear of blood inside one of the buffs eggs.
Thanks.

 

[Pumpkinpup]

You can grind up a couple of tablets and stir it into a treat like yogurt every couple of weeks. That is what I do with my birds when they need something like vitamins.