Thiamine (B) is generally recognized as safe in pregnancy and is in fact critical to prevent deficiency in pregnant patients with prolonged vomiting
An alternative: Measuring urine levels of xanthurenic acid following intake of a high dose of tryptophan

Chan School of Public Health: "Vitamin B12." Inflammatory Bowel Diseases: "Prevalence of and risk factors for vitamin B(12) deficiency in patients with Crohn's disease," "Vitamin B12 deficiency in inflammatory bowel disease: prevalence, risk factors, evaluation, and management." MedlinePlus: "Cyanocobalamin Injection." National Health Services: "Hydroxocobalamin," "Treatment -Vitamin B12 or folate deficiency anaemia Contents," "Vitamin B12." Nutrition Reviews: "How prevalent is vitamin B(12) deficiency among vegetarians?" Surgery for Obesity and Related Diseases: "Vitamin B12 deficiency in patients undergoing bariatric surgery: preventive strategies and key recommendations." The American Journal of Clinical Nutrition: "How common is vitamin B-12 deficiency?" The American Journal of Gastroenterology: "Vitamin B12 deficiency in untreated celiac disease." Top B12 Injections Who Get Them, How Quickly They Work Related Articles 22 Healthy Foods High in B VitaminsAny deficiency of B vitamins can lead to various health conditions

1=10 2=20 3=30 4=40 5=50 - 1 Box of 50 = $101.95 Discounts below the bullet descriptions Each 2ml ampule contains 500mg Vitamin C (Ascorbic acid) 1 dose per ampoule For Intramuscular or intravenous injection Vegan Friendly GMP & PIC/S Quality is Guaranteed Date Code Expires: AUG 27' Maximum 40 per order (400amps) This product should only be used under professional healthcare guidance and support 10.00 Flat fee shipping, avg
Its when its over the limits that the body will struggle to cope
These can include hives and redness at the injection site