The ratio of Firmicutes to Bacteroidetes is a commonly-studied change with an increase often linked to HFD consumption/obesity in mice 43,44 and humans 45,46 (for review, see John and Mullin, 2016 47 )
For individuals requiring supplementation due to confirmed deficiency or malabsorption, therapeutic doses vary considerably depending on the underlying cause: Dietary deficiency : 50150 micrograms daily orally, or cyanocobalamin tablets as prescribed Pernicious anaemia : Initially hydroxocobalamin 1 mg intramuscularly three times weekly for two weeks, then maintenance injections every two to three months [3] Neurological involvement : More intensive regimens may be required, with hydroxocobalamin injections on alternate days until symptom improvement [3] NICE guidance emphasises that supplementation should be evidence-based rather than speculative
[5] This is an emerging area of interest, particularly for patients dealing with both excess weight and degenerative joint disease
B12 deficiency is quite common in both the US and UK, affecting around 6% of people aged under 60, and nearly 20% of those 60 and over