These vitamins are all essential for your health and wellbeing. Vitamin B12 is particularly important for those on a plant-based diet. Low levels of Vitamin B12 and Folate can have severe effects on blood and overall health. Vitamin D is also very important for anyone living in the UK. Up to a quarter of the population is low in Vitamin D at the end of winter. Low levels can cause a long list of health problems including fatigue, bone & muscle pain, depression and more.