Would this diet be missing anything?

I've had 3 vegan friends who had B-12 deficiency. Other 2 (Stupid ones who didn't know what they were doing, they tried to live on salads-I don't blame veganism but their ignorance for the circumstances) had skin problems, got weak (Also bad nail and hair and had zinc defficiency) one of whom has recently switched to a vegetarian diet and she's still saying she'll get back to vegan when she's better. Another one went vegan for 3 years, she got sick, I mean sick, to the point where she's switched to meat-only diet now (Another extreme edge) and claims she has stomach cramps whenever she has a bit of veggies. She's been on that diet for over a year now, she regularly gets checked (She has to, due to problems she had on a vegan diet) and has no defficiency. Also, my gf's grandmother had hypercholesterolemia and doctor told her not to eat eggs and meat at all. Her case didn't get any better, as a bonus she got b-12 defficiency on the side. I have another friend who has gone vegan recently, we'll see how it goes. I only have those 7 vegan/vegetarian friends, as they don't form the majority of the population. But just like meat eaters who think they'll get all they need from chicken breasts and salads (Or confuse meat eating with trans fats and McDonalds burgers, which is mostly fried potatoes, white bread and all that crap), a lot of vegans/vegetarians don't know much either. If you are aware you'll have harder time to get your daily requirements and most likely you'll need supplementation of this or that, then go ahead. But speaking as if it's the easiest thing to reach your daily needs while keeping your calories low enough or without getting bloated with 1kg spinach per day is plain wrong.

http://www.ncbi.nlm.nih.gov/pubmed/683264?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=74

http://www.ncbi.nlm.nih.gov/pubmed/15338248?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=1

http://www.ajcn.org/cgi/content/full/72/3/762

http://www.ncbi.nlm.nih.gov/pubmed/502936?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=72

http://www.ncbi.nlm.nih.gov/pubmed/3948463?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_SingleItemSupl.Pubmed_Discovery_RA&linkpos=2&log$=relatedarticles&logdbfrom=pubmed

http://www.ncbi.nlm.nih.gov/pubmed/19676146?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=2

http://www.ncbi.nlm.nih.gov/pubmed/19852900?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_SingleItemSupl.Pubmed_Discovery_RA&linkpos=3&log$=relatedarticles&logdbfrom=pubmed

http://www.ncbi.nlm.nih.gov/pubmed/11787236?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_SingleItemSupl.Pubmed_Discovery_RA&linkpos=2&log$=relatedarticles&logdbfrom=pubmed

http://www.ncbi.nlm.nih.gov/pubmed/2635448?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=65

http://www.ncbi.nlm.nih.gov/pubmed/3677536?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=67

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1141584/?tool=pubmed

http://www.jstage.jst.go.jp/article/internalmedicine/45/10/705/_pdf

I don't know what exactly is in quorn burgers. But whole eggs balance out a vegetarian's diet even better than egg whites and chicken breasts balance out the diet of meat eaters that are afraid to eat meat and yolks.