Pins and needles, tingling and numbness in the tips of fingers and toes can also develop from low folic acid or folate deficiency following ongoing high Vitamin B12 supplementation or injections, which is why folate status should always be checked whenever Vitamin B12 is taken for longer periods of time. The same applies when folic acid is regularly supplemented, which can likewise lead to Vitamin B12 deficiency and the typical tingling and numbness symptoms, with the potential of causing permanent nerve damage... Full Text