When women have children, several things can happen.
1) you may be hypothyroid...after delivery. This happens fairly commonly. So I would get that tested. Tingling and or numbness in the hands and feet are one sign of low thyroid functioning.
2) you may develop an autoimmune disorder after delivery. This is when they turn up if they turn up. This can be evaluated with blood tests.
3) you may be very low in Vit D. New data is coming out on Vit D and health. There is new data on the correct new dosage for infants that are breastfeeding too.
4) you may be depleted in essential fatty acids, since the baby takes enormous amounts of Omega-3s (esp DHA) to develop the brain. There is a supplement made especially for pregnant and nursing mothers-- Expecta:
If you did not take the new prenatals with Omega-3s in them, I'd seriously suggest you start this ASAP. It will help both you and your new baby.
5) I would get tested for B12 levels so you know where you are.
Also at this time get the Vit D test, so you will know how much to take.
As far as I know, B12 is not harmful for the baby. And if you were low during the pregnancy the baby may be low too.
These are the basic nutritional stresses that occur after delivery.
If you do not eat foods that provide magnesium (almonds, figs, oatmeal, beans, Edamame beans, yogurt), you may need this mineral. I'd suggest trying to eat more foods high in this until you find out the other test results.