Hmmm! Interesting. Something we've discussed a lot here on CureZone is the problem with filtered water. You can't not drink filtered water because tap water sucks, but there are problems with filtered water too. The filters remove all the good alkaloids right along with the bad minerals, so you end up with a kind of dead, negatively charged water that not only doesn't give you minerals but also attracts good minerals to neutralize the water and that means it leaches you of good minerals.
So you need to add a good Sea Salt to your diet, use that instead of table salt whenever possible, and see about getting more minerals into your diet in other ways. You can spike your water wtih bottled liquid trace minerals; take EmergenC or another supplement; eat more dark, leafy greens, broths and whole grains.
Numbness and itching both is all about the quality of the tissue and the nerves/blood feeding it. That means minerals, essential fatty acids, and removing whatever blockages are there to the circulation.
I'm not a nervous system anatomy expert so I'm not sure if there's anywhere along the spine/pelvis that could affect both feet. But I think the nerve branches for each leg are totally separate, so that means the circulatory problem is probably vascular or cellular. The odds of both feet suffering nervous constriction is pretty low unless you bought a pair of really cruel shoes. ;) Cellular means lack of minerals/electrolytes, vascular means cayenne pepper tincture, light exercise and occasionally elevating your feet would help.
Oh and try a foot bath with Epsom Salts and baking soda every night for half an hour. :) That will help to ionize the area. A good large handful of Epsom, a smaller handful of the baking soda.