People, who have had bariatric surgery procedures such as sleeve gastrectomy, Roux-en-y gastric bypass, duodenal switch, one anastomosis (mini) gastric bypass, single anastomosis duodenal ileal switch (SADIS), have reduced absorption of vitamin B12 and increased risk of developing vitamin B12 deficiency.
Vitamin B12 deficiency may go undetected and is masked by folic acid. Untreated vitamin B12 deficiency may result in subacute combined degeneration of spinal cord or irreversible neuropathy, which may occur in the absence of megaloblastic anaemia.
Consequently, the recommended treatment regimen to avoid deficiency is an intramuscular vitamin B12 injection every three months. Some people require more frequent injections and would usually be guided by specialist hospital colleagues.
As a result of pressures on services, and the requirement of vulnerable groups to self-isolate, people are unable to access timely vitamin B12 injections. This is causing anxiety for many. The British Obesity and Metabolic Surgery Society (BOMSS) recommend the following as an interim measure:
For people who have had bariatric procedures (see opening paragraph) which affect vitamin B12 absorption:
BOMSS, Royal College of General Practitioners and the British Dietetic Association do not endorse any particular brand of oral supplementation, however patients may wish to source oral vitamin B12 as below. Details are correct at the time of writing.
Note the symbol for micrograms is μg and this may be used on some ingredient lists: