Hi. The vitamin D deficiency needs to be treated with a capsule or a sachet which are ideal ( e.g. cap. Uprise D3 (60k) once a week after lunch). B12 also needs to be corrected via injections or oral tablet (e.g. Tab. 2 B12 once daily after lunch). If u have non-veg diet then that's also good source of B12. I would not directly correlate these to any skin infection (especially the pic u have sent - there is no direct relation). The likelyhood of the lesion u sent via pic being a mile is possible. Other possibilities being dermatofibroma or pickers nodule. Get it thoroughly inspected n examined for proper diagnosis n thereby treatment. Surgical excision may be the option here if u wish to get it removed. Regards, Dr. Zubin Mandlewala MUMBAI