[nanakante]

It sounds like your body is reacting to fixing that B12 deficiency, and that might be the reason you're feeling those tingling sensations in your breasts—sometimes that's just a sign of hormonal shifts. Looking at your lab results and symptoms, it's possible you could notice your breasts growing a bit more as your estrogen levels get back in balance. 

To help things along, focusing on good nutrition, staying active, and checking in with a healthcare provider to keep an eye on your hormones can make a difference. However, remember that any changes are typically slow and subtle.