Since I started studying nutritional science (Yes, food and its involvement in the body is science- it's chemistry and physiology), it's started becoming really frustrating to see all the misinformation out there, even here on Unleashed about vegan nutrition and health.
Nutrition is so, so important for our health. Good nutrition can increase livelihood and energy, prevent disease, maintain healthy body weight and so much more. Fortunately for us, lacto-ovo vegetarians and vegan vegetarians exclude animal protein (although not all is excluded by lacto-ovo vegetarians), which decreases the likelihood of many cancers, diabetes mellitus and other diseases like heart disease and obesity.
But there's a lot of misinformation regarding the "health risks" or "problem areas" of these diets. A lot of people on the Internet, even on this forum recommend a plethora of multivitamins and supplements. I'd like to use the knowledge I am gaining from my degree and the information I sought specifically from my lecturer, lab tech and tutor, as well as various peer reviewed articles and text books to clear some of this up. I'm not an expert *YET*, but I'm closer to it than many others, and I have picked the brains of experts.
So here's what it boils down to...
Protein? Don't even worry. When people tell you that plant protein is a lower "quality", all it means is that you cannot gain ALL of the essential amino acids from one single plant source. As a broad, general rule, dieticians recommend eating a variety of legumes, nuts, grains, and corn to gain a full spectrum of amino acids. Those lacking in lentils are present in brown rice, and vice versa, so dahl with rice is a complete protein food. You get my drift? Also, in Western nations protein deficiency is almost completely unheard of. Protein excess is more our problem.
Iron? This is up to the individual. Non-haem (plant) iron is less accessible than haem (animal) iron. This means that we need to consume more than individuals who consume animal products to actually gain the same yield of iron. I could explain exactly how this works and why it works this way, but this is getting pretty long as is. Avoiding tea, coffee, spinach, red wine and other foods containing tannin within two hours either side of an iron rich meal will increase your yield of iron. Yeah, I said spinach. While it does contain iron, spinach actually acts as a sort of roadblock to non-haem iron absorption. Broccoli, almonds, lentils, whole grains, legumes and Asian greens are much better sources.
Unless you show signs of a deficiency disease, there is no real need to supplement your iron intake; however I personally take a 40mg iron supplement once a fortnight simply because I am a very busy female of menstruating age, and that means that my iron requirements are higher than most people, but my lifestyle doesn't always lend itself to healthy eating.
Omega 3? Here's the doozey. I have heard all sorts of things about this, so I went to my lecturer for clarification. Fatty acids are essentially hydrocarbon chains, and the human body cannot synthesize chains 18 carbons long or more. This means that we must gain these fatty acids elsewhere. Alpha-linolenic acid and linoleic acid are the 18 carbon long fatty acids from the n-3 and n-6 group, the "precursers" to Omega 3 DHA and EPA if you will. If you eat these, found in rapeseed (canola) oil and other plant sources such as flax and chia, then your body can synthesize DHA and EPA (20 and 22 carbons in a chain). That said, while it is not NECESSARY to supplement Omega 3, I still take one once a week. A good vegan supplement, Opti3, is found here: http://www.greenedgeonline.com.au/acatalog/Essential_Fatty_Acids.html
Vitamin B12? Is it in mushroom? Ehh, that's debatable. Either way, it's important. I use nutritional yeast wherever possible, drink fortified soy and almond milk, and when I'm short on time I grab some fortified burger patties. While I do HAVE B12 sublingual supplements, I rarely find myself in a situation where I frequently come low enough under my RDI to take one. If you don't consume around 10 micrograms a day (keeping in mind that while the RDI is lower, it's not the most easily absorbed nutrient), it's probably not a bad idea to have a sublingual.
Finally, calcium. Fortified non dairy milks, almonds and fortified soy yoghurts are your best bet. My personal favourite is Almond Breeze, the only almond milk I've ever found to be fortified with calcium. When you shop for non dairy milks, check the nutrition panel. If it does not say at least 300mg of calcium per serve, put it back and keep looking. If you have as many serves of that as you would dairy in a day, then you're set for calcium and you should not need to worry about a supplement at all.
Most importantly, remember, it is not a good idea to rely on supplements for good nutrition. The best nutrition comes from food. Supplements are rarely recommended by dieticians unless you show signs of deficiency disease. They should be a back up, not what you rely on. I don't take a daily multivitamin. Once a week I take a DHA/EPA supplement, once a fortnight I take iron, but only because of my non-stop lifestyle (work, uni, work, uni, work , uni, work work work, UNI UNI UNI, work
) If I were male, I wouldn't even worry about it with my lifestyle. If I'm separated from my nutritional yeast and fortified milks/mock meats, then I might take a sublingual for vitamin B12. Other than that, there's really no need as long as you take good care of yourself.
I hope someone out there finds this useful, and don't get sucked in by vitamin companies.