I suspect that your numbness could be peripheral neuropathy (PN) caused by a vitamin B12 deficiency. This is despite your information that:
They did check my B12 and folate, said they were normal.
Here is why:
1. Numbness is not a typical symptom of iron deficiency - fatigue and sore tongue are common
2. Numbness is not a typical symptom of vitamin D deficiency
3. Numbness is a typical symptom of vitamin B12 deficiency; so also are fatigue and painful tongue, as well as many other symptoms
So, I think that the answer to your question:
The dr. says the low iron and low vitamin D explain the numbness. Is this true?
is that you are right to question it.
I should point out that PN can be caused by many problems other than B12 deficiency. I also am not suggesting that you do not have iron and vitamin D deficiency; just that they do not explain the numbness.
I suggest that you read some of the information provided by Mayo. Here are links to the most relevant pages:
Iron Deficiency - symptoms
Vitamin D Deficiency: What a Pain it is
Peripheral Neuropathy - causes
There are many other useful sources of information about iron and vitamin D deficiency, and PN, available on the Internet, but I suggest that you read these ones first.
If you do investigate the possibility of vitamin B12 deficiency, then I suggest that you read my post #27 on this thread first:
I also invite you to visit my web site (URL and link at end of this message), and read all of the pages in Information and Advice for Patients
As you will see, serum B12 is not a good indicator of vitamin B12 deficiency, and I recommend using methylmalonic acid. As I have said, in the above thread and on my web site:
It is essential that, for diagnosis of B12 deficiency, you do not take any form of B12 supplements or injections before having these tests.
Please tell us:
1. What were your serum folate and B12 results, and the date of the test? Please include the units, because the labs have not all adopted the newer SI units. For example, for serum B12, some labs use pmol/L while others still use ng/L (= pg/mL).
2. Were you tested for red-cell folate, as well as for serum folate (folic acid) and, if so, what was the result?
3. Did you take any form of vitamin B12 or folate supplements before the test and, if so, what type, how much, how often?
how long before I'll feel better? Am I going to feel this way forever???
No, you will not feel this way forever, but you do need to have a proper diagnosis of the cause of your numbness. Once you do that, and then commence appropriate treatment, you will improve. How long this takes will depend on what the problem is, how far any damage has gone, and how well you treat it, as well as many other factors. For example, peripheral nerve damage from B12 deficiency can take many months, or even years, to completely repair.