Vitamins

What is a vitamin?

A vitamin is an organic compound required as a nutrient in tiny amounts. A compound is called a vitamin when it cannot be synthesized in sufficient quantities by the body and must be obtained from the diet.

Vitamins are defined by their biological activity, not their structure and each "vitamin" actually refers to a number of 'vitamer' compounds.

Vitamers are often inter-convertible (they can be made into each other) in the body. The term vitamin does not include other essential nutrients such as dietary minerals, essential fatty acids, or essential amino acids, nor does it encompass the large number of other nutrients that promote health but that are not essential.

Vitamins have diverse biochemical functions, including acting as hormones (e.g. vitamin D), antioxidants (e.g. vitamin E), and helping with cell and tissue growth and differentiation (e.g. vitamin A). The largest number of vitamins (the B complex vitamins) are used to make 'coenzymes' that are used in metabolism.

Until around 200 years ago, vitamins were obtained solely through food intake, meaning any changes in the diet would alter the types and amounts of vitamins ingested. Vitamins have only been made widely available as inexpensive pills inseveral decades, allowing us to supplement the 'natural' vitamins we get from our diet.



Where do vegans get their vitamins from? Should they supplement?

Apart from Vitamin B12, which is found in micro-organisms and is hard to obtain from plant sources, vegans don't really need to supplement any more than non-vegans do; the specific supplements you should take, if any, will depend on how healthy and balanced your diet is (which is easy if you're eating lots of veggies as these are the best sources of Vitamins A, B1-9, C, E and K).



So, what about Vitamin B12?

Vitamin B12 is unique amongst the vitamins in that it is not synthesised by either plants or animals - only bacteria actually have the enzymes necessary to create it!

B12 is also the most important vitamin for vegans as it is not easy to get enough B12 from plants sources (this might partly be because we wash plants too thoroughly - MIT researchers have found that the bacteria that produce B12 may live in the soil around the root networks of plants we eat!) and also because the side effects of B12 are quite serious: anemia, nerve damage, etc.

Even though your body stores B12 for a long time (you only lose around 0.1% of your reserves per day), it will eventually run out if you're not taking enough in, and most doctors thus recommend a regular B12 supplement of 3µg (micrograms) per day. This is recommended for meat-eaters too, as they can also suffer from B12 deficiency due to the fact that some peoples' bodies don't process it properly, especially as they get older.

Vitamin B12 is also widely available in breakfast cereals, soymilk, energy drinks (although the caffeine in these drinks might interfere with absorption) and meat substitutes. Some brands of nutritional yeast are also a reliable source for this vitamin and most common multivitamins also contain B12 (we recommend Viridian multi-vits - they come in vegecaps and have high, bio-available amounts of most of the vitamins and minerals you need).

NB: Some vegan sites say you can get B12 from tempeh, seaweed, mushrooms, nori and so forth. Research indicates that these are NOT reliable sources though, so please be responsible and take a supplement or fortified foods. Also ensure that, vegan or not, you're getting your B12 levels checked frequently, especially if you're pregnant or breast-feeding! Refer to our B12 article for more information.