No. All the nutrients you need – with perhaps one exception – can be found easily and plentifully in a vegan diet. That one exception is Vitamin B12.
It is possible to get enough of this vitamin on a vegan diet if you eat plenty of yeast extract, fortified plant milks and breakfast cereals but it is not worth risking being deficient so the advice is to take a daily supplement to be 100 per cent sure you are getting enough.
Vitamin B12 is needed to keep our nervous systems, DNA and red blood cells healthy, and it’s not just vegans who need to keep an eye on their B12 intake. People with pernicious anaemia or who suffer from Crohn’s or lupus, or who drink heavily, are at risk of being deficient. Since the risk of deficiency increases with age, the advice given in the US is for everyone over the age of 50 to take a daily B12 supplement regardless of their dietary choices.
Why do vegans need to supplement it? Well, the vitamin is found in animal products but it is not made by the animals themselves but by bacteria that live inside them. The B12 used in vegan supplements or fortified foods such as Marmite is made by ‘farming’ the bacteria directly and harvesting the vitamin. It’s the same substance made in exactly the same way so it’s not unnatural, or in any case, it’s no more unnatural than any other use of microorganisms in bread, cheese, yoghurt, wine or beer. And it’s a LOT more natural than some of the processed foods we all sometimes eat.
As for all those other vitamins, minerals and nutrients, you’ll find them aplenty if you eat a varied vegan diet. Take a look at Dr Michael Greger’s Daily Dozen chart to guide you as to what else we should be eating for optimum nutrition.