Vitamin B12 deficiency
Conditions
Interventions
Group 1: Long-term vegan diet (= 2 years) prior to study inclusion
Group 2: Long-term vegetarian diet (= 2 years) prior to study inclusion
Group 3: Long-term mixed diet (= 2 years) prior to study incl
Sponsors
Universitätsklinikum Freiburg, Klinik für Innere Medizin II, Uni-Zentrum Naturheilkunde
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Inclusion criteria
Inclusion criteria: Only individuals aged 18 years or older that are capable of giving informed consent will be considered. Eligible persons must speak and understand German and should be willing to complete a nutritional protocol. Only individuals consuming a mixed diet, a lacto-ovo-vegetarian diet or a vegan diet for at least two years (without major dietary modifications or interruptions) will be considered. The aforementioned dietary patterns are defined as follows. The mixed diet includes at least one of the following foods: meat, poultry, fish, seafood and dairy in conjunction with staple foods such as rice, potatoes, grains, etc. The lacto-ovo-vegetarian diet excludes meat and fish but includes dairy products and/or eggs. The vegan diet excludes all animal flesh products as well as dairy and eggs.
Exclusion criteria
Exclusion criteria: - acute or chronic medical conditions that may affect the study’s primary outcome, such as acute / chronic infections, autoimmune disorders, and tumor diseases - persons that are unable to speak and understand German may not participate in this trial - pregnancy or lactation, delivery within the last 12 months - daily nicotine abuse - the intake of a medication that may affect Vitamin B12 uptake / resorption, such as Metformin, PPIs and Antacids. - eating disorders, a BMI 29.9 kg/m2 - alcohol intake (>30 g/day), - participation in another clinical trial within the last 4 weeks - blood donations within the last 6 weeks.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Metabolimic profiling of vitamin B12 metabolism, as assessed by the cB12-Index (Combined indicator of vitamin B 12 status). The cB12-Index introduced by Sergey Fedosov et al. includes serum vitamin B12, holotranscobalamine, methylmalonic acid , folic acid and homocysteine, and patient age. | — |
Secondary
| Measure | Time frame |
|---|---|
| - Metabolomic analyses of fatty acid metabolism, as measured by a detailed fatty acid profile which includes the following fatty acids: - saturated fatty acids (myristic acid, palmitic acid, stearic acid, behenic acid); - monounsaturated fatty acids (palmitic acid, oleic acid), polyunsaturated fatty acids (alpha-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid), - polyunsaturated fatty acids (linoleic acid, gamma-linolenic acid, homo-gama-linolenic acid, arachidonic acid), cholesterol and triglycerides (cholesterol, LDL, HDL, triglycerides). - Metabolomic analyses of metabolism, as measured by: plasma, urine and stool samples (microbiome metabolites. These include profiles of essential and non-essential amino acids, sulfur metabolism, methionine and folate cycle metabolites (methionine, cystathionine, homocysteine, cysteine, glutathione (GSH), sulfo-cysteine, methionine sulfoxide (MSO), taurine, hypotaurine, homotaurine, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), lanthionine); Vitamin B12 biomarkers (holotranscobalamin, serum vitamin B12 and its metabolites, serum homocysteine (Hcy), serum methylmalonic acid (MMA)), energy status (glycolysis and Krebs cycle intermediates), acylcarnitines profile (short, medium and long chain acylcarnitines, free carnitine, hydroxylated acylcarnitines, dicarboxylated fatty acids), and, finally microbiome-produced metabolites (microbiome metabolite panel (glutamine, leucine, TMAO, acetate, glucose, glycerol, cobalamin analogs, etc). - Macro- and micronutrient distribution across the different diets (as measured by 4-day weighing protocols which we plan to analyze with specific nutrition software (Nutri-Guide nutrition software, version 4.9, Nutri-Science GmbH). We will calculate Potential Renal Acid Load (PRAL) and Net Endogenous Acid Production (NEAP) scores based on those protocols. Both serve as important markers of dietary acid load. - Other laboratory parameters including CBC, HbA1c, BUN, uric acid | — |
Countries
Germany
Contacts
Public ContactMaximilian Storz
Universitätsklinik Freiburg, Klinik für Innere Medizin II, Uni-Zentrum Naturheilkunde
Outcome results
None listed