Na has a larger hydrated radius and it’s harder to remove the water molecules (takes more energy) then potassium (K). This seems to be why K is intracellular and Na predominately extracellular. When there’s a phase change Na (and Ca) come in and K and Mg leave. However, this is supposed to reverse again as the cytoplasm restructures. The monovalent cations can then bind to proteins (again why K would be desirable) the divalent hold different proteins together, etc.

So, B1, helping to structure the cellular water (increased ATP, etc) should allow for thins like K and Mg to stop being wasted. This then will cause aldosterone to normalize, etc so yes, the need for Na should decrease.