"Is being vegan healthy?"
Being vegan is healthy for many. However it's also misunderstood, by many what being a vegan means. A vegan is someone who not only follows a vegetarian diet, but also excludes the use of all animal products, in their life. This mean not only not eating diary, eggs, fish/seafood, honey (although there's some disagreement on this with some vegans), and meat, but also excludes buy leather, silk and will, and any other products that are derived from animals, along with personal care items.
Following a strict vegetarian diet, can be healthy for many and it's true, it's not suitable for everyone, yet many will declare emphatically otherwise. There's only one nutrient missing from the strict vegetarian diet, as adhered to by vegans. That is vitamin B12. Another two that's hard to attain, and this is on any diet, is vitamin D3, and finally vitamin K2, which should NOT be confused with vitamin K or to those knowledgeable vitamin K1.
A strict vegetarian diet, requires at minimum the eating of either foods fortified in vitamin B12, and it's also very strongly recommended that a vitamin B12 supplement be taken as insurance. The reason for this is that there is no known, or proven plant based source, for vitamin B 12. Now there are some vegans, and strict vegetarians who will state otherwise. Only a very rare few has actually managed to go more than ten years, without it. Their bodies happen to be among those rare few that somehow manages to recycle it. However that is NOT to say that at some point, they're going to run out of it. Which most of those will. On average most people's body's can store between two and seven years worth of vitamin B12, with an average of three to five years. Of all of the B complex vitamins, vitamin B12 is unique in this aspect.
Vitamin K, or the K complex/family has more than a single type, or isomer. There are two main types. Vitamin K1, or the phylloquinone, are easily gotten from plant based foods. However vitamin K2, or the menaquinones, are not. They're found naturally in meat, and some other animal based products. No plant contains vitamin K2, naturally, as it requires a chemical change of vitamin K1 in either the body, or by fermentation, of food, with bacteria. Similar to vitamin B12. However while the roles of vitamin K1, and vitamin K2 are similar they're also reversed, as evidence has shown. Vitamin K2 is found in it's greatest amounts in fermented soy beans, known as natto. The vitamin K complex or group, are also somewhat unique, in the fat soluble vitamins, ion the the body doesn't store them very long. However vitamin K2, for which there's several sub-types, or isomers, has a half life of of up to seventy two hours, and vitamin K as a whole, can become completely depleted within about two weeks. However vitamin K is not an issue for most vegetarians.
Vitamin D, or more specifically vitamin D3, while its known as the sunshine vitamin, has to date only one known, and proven plant based source. That's a specific type of lichen, that is now being used by some vitamin makers, to produce a strict vegetarian/vegan suitable supplement. Vitamin D3, is found in some small amounts in certain meats, along with some dairy, and in eggs. It is however found in its highest quantity in fish/seafood. However a vitamin D deficiency, is actually one of the most common ones found in people.
If someone who wants to be a vegetarian, or a vegan, and wants to follow a strict vegetarian diet, they should at least supplement vitamin B12, then consider strongly a vitamin D3, and vitamin K2 supplement. However a good quality general multivitamin should cover all but vitamin K2, and specifically the vitamin K2-MK7 form. Most, if not all multivitamins contains vitamin K1.
Now not everyone can follow the strict vegetarian diet, as followed by those who are vegan. There has even been nutritional experts who knows how to eat, and where to get, or otherwise supplement, that's suffered what's known as failure to thrive. By experts, I mean those who have a degree in nutrition, such as a nutritionist, or are medical dietitians. So I'm not talking about your person who has on their own, spent hundreds or thousands of hours, or even over a course of many years, of their time, doing research, studying, and learning about nutrition. Now there are no special or unique properties to meat, or other animal products, that's known.
A strict vegetarian diet can in fact be a healthy dietary lifestyle for many, provided that it's done properly. Now I do eat meat, but not in large amounts. However for reasons unknown to me, I along with my late girlfriend, a number of years ago, for some reason, couldn't make a lacto-ovo-vegetarian work. The whole blood type diet, can be tossed out the window, as she was a type O, and I'm a type A blood type. Between the two of us, we both had a number of years, learning about nutrition, and out of necessity. Our failure to thrive though, WILL NOT PREVENT me from trying to assist those, who are interested in becoming a vegetarian, or following the vegan lifestyle. This of course gets me into trouble at times, with others who eats meat. If I have to take some knocks, here and there, from either side of the dietary aisle, then so be it.