Figures show millions of people across the UK are deficient in vitamin B12 . This can leave sufferers with a range of symptoms including feeling shattered and with brain fog, depression and muscle weakness . While many people should be able to get all the B12 they need from their diet some groups stuggle to get sufficient. These include vegans and others who do not eat meat, fish or dairy foods as the vitamin is not found naturally in foods such as fruit, vegetables and grains. Now scientists