Or any trace mineral supplement. Take something similar, along with all of the companions, Boron, plenty of C, Vit. D, and a B-complex (or temporarily avoid the B-complex if your heart palpitations continue), and you should be good. I also take at least 1 Tbsp of Organic unsulphured Blackstrap Molasses for extra iron and Potassium...
Of course, it also depends what you are deficient in...