I have some pretty noticeable dark vein like mark near one side of my mouth. Is it due to some deficiency? Natural way removal?

Treatment options here include sclerotherapy or laser with the ND YAG 1064 nm laser or the KTP laser. The KTP laser is KTP laser is energised through a beam generated by a neodynium:yitrium aluminium garnet ND YAG laser. This is directed through the KTP crystal to produce a beam in the green visible spectrum and has a wavelength of 532 nm.

If you have a vein in this area then it can usually be treated by sclerotherapy, laser or IPL.  Depending on its size, VeinWave, VeinGogh or even microneedle radiofrequency may be possible. Nutritional deficiencies will not cause veins to form.  See a Vein Specialist.