Yes, Vit B12 deficiency causes feeling cold, tiredness, dizziness etc. Low intrinsic factor in gut that
hampers absorption, pernicious anemia, parasites in the gut, diet poor in Vit B12, Crohn;s disease, IBS, or poor metabolism by liver are the causes behind it. Please consult a doctor to rule these out. Take a diet rich in Vit B12 which should include meat and animal products, cheese, such as beef, liver, salmon, cod, and eggs.