If fowls do not have any deficiency,they will be of no value and just be wasted or can cause poisoning just like in iron.There is a balance of each and giving more to one will cause a drop in the other.Example is potassium.If you give too of it much, sodium levels will drop.B vitamins are more safer to use because they are water soluble and excess can be excreted right away.How ever the other vitam