Yes.  But it’s the lack of aldsoterone that leads to sodium deficiency in CAH’ ers.  Cortisol has some sodium retaining properties, but as great as aldosterone does.  If your hair analysis shows sodium lack to such an extent I’d look at testing renin levels and also sodium levels in the blood.  Renin would be raised and sodium levels would be low in the blood also as well as in the hair if this is the case. This will tell you if you need aldosterone replacement in the way of florinef or floudrocortisone.