Failure to recognise B12 deficiency may be costing the country billions of pounds in lost tax, lost quality of life, and costs to the NHS. As only the costs to the NHS can be calculated with any accuracy, let's look at these.
For the purposes of the calculations we’ve used the 2007/08 census and prevalence figures, and only used the number of patients suffering from specific named conditions, i.e. 2 million, so the actual benefits may be much higher.
In simple terms, the cost of screening 2 million people from B12 deficiency would be around £6.7 million (one off cost), and assuming that 30% of these required injections and the remainder oral tablets, treatment costs would be £118.3 million per year.
This would save at least £854 million per year, specifically on medication costs to the NHS (i.e. not including social services or care costs and all of the other more nebulous costs), and even then we've excluded a lot of savings which we considered "too difficult to estimate" so this is a very conservative figure. This only represents around 5% of the total NHS medicines budget, which is reassuring considering the number of patients being treated.