can vitamin b12 injection cause diarrhea Shots at Home: How, Where & How Often to Inject Yourself Doctor explains clinical signs of

Vitamin B12 supplementation is important in discrete populations People who don't consume animal flesh run the risk of vitamin B12 deficiency that is, unless they take supplements or regularly eat foods fortified with the nutrient, including fortified cereals, fortified plant milks, and fortified nutritional yeast, according to The Vegetarian Resource Group

The nausea and vomiting was worse in the beginning weeks and slowly got better

Lifestyle factors Busy schedules often favor weekly weight loss shots rather than daily injections

Another group thats at-risk for low B12 levels are those who have had gastric bypass surgery or have other stomach issues, such as ulcers