I doubt prenatals contain much potassium but other vitamins might so please be careful as your nails and hair are not worth the risk if you are taking spiro. E itself causes thicker and longer growth. And a calcium citrate will help your nails. The vitamins could lead to hyperkalemia (excess potasium) a medical emergency due to the risk of potentially fatal abnormal heart rhythm. If not, well, idk. I'm only trying to help. Plus, vitamins are processed by the liver and enzyme CYP450, largely. If you're orally taking E that could be bad as well. Sublinqual admin or shots of E prob not so much. Id's seriously call your doc to make sure its okay. Plus, prenatals are meant for pregnant women and the reason it may help with hair is the iron in them. But iron is hard on the liver. Your call. How long have u been on HRT?