<s>[INST] hi  I am pregnant and in the process of having my bloods tested for b12 deficiency.  I just wondered if one of the side affects could be swelling to my face/eyes and lips as I wake up most mornings with bacd red burning swelling to my face.  Im feeling very tired and down. thanks [/INST] Hi, welcome and thanks for asking. Looking at the clinical symptoms and suspected b12 deficiency, I am of the opinion that it does not cause. Edema of the face is usually of renal cause and here, the pregnant uterus could be compressing the renal arteries, causing the kidney to retain more fluid. As it appears more in the morning, try to change your sleeping position, it could help. Vitamin B12 deficiency does not cause swelling in face. Any further queries, happy to help again. </s>