Vegans are deficit in b12:
http://jamanetwork.com/journals/jamaneurology/fullarticle/784788 https://www.ncbi.nlm.nih.gov/pubmed/16219987
High fiber diets reduce serum half life of vitamin D3:
https://www.ncbi.nlm.nih.gov/pubmed/6299329
Vegans have weaker bones due to lower calcium intake and vitamin D3 levels:
http://jamanetwork.com/journals/jamainternalmedicine/fullarticle/486478 https://www.ncbi.nlm.nih.gov/pubmed/21092700
Vegans have a worse memory compared to non vegans due to creatine deficiency in vegans:
https://www.ncbi.nlm.nih.gov/pubmed/21118604 https://www.ncbi.nlm.nih.gov/pubmed/14561278
Vegans have less gains compared to non vegans:
http://m.ajcn.nutrition.org/content/70/6/1032.full
Vegans are deficient in omega threes:
https://www.ncbi.nlm.nih.gov/pubmed/16087975 https://www.ncbi.nlm.nih.gov/pubmed/16188209 https://www.ncbi.nlm.nih.gov/pubmed/12323090 https://www.ncbi.nlm.nih.gov/pubmed/12323085
Vegans are deficit in carnitine:
https://www.ncbi.nlm.nih.gov/pubmed/21753065 https://www.ncbi.nlm.nih.gov/pubmed/2756917 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1628441/ https://www.ncbi.nlm.nih.gov/pubmed/11043928
Vegans are deficient in taurine:
https://www.ncbi.nlm.nih.gov/pubmed/3354491
Vegans are deficient in iodine:
https://www.ncbi.nlm.nih.gov/pubmed/12748410 https://www.ncbi.nlm.nih.gov/pubmed/21613354
Vegans are deficient in Coenzyme Q10:
https://www.ncbi.nlm.nih.gov/pubmed/16873950
Vegans are deficient in iron due to the fact that iron from plant sources is less bioavailable than iron from meat sources:
https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/ https://www.ncbi.nlm.nih.gov/pubmed/11269606
Vegans are deficient in vitamin A:
https://www.ncbi.nlm.nih.gov/pubmed/19103647 http://m.jn.nutrition.org/content/137/11/2346.full
Vegans have a lower sperm count than non vegans:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257705/ https://www.ncbi.nlm.nih.gov/pubmed/35465
Vegans have lower testosterone than non vegans:
https://www.ncbi.nlm.nih.gov/pubmed/1435181 http://m.ajcn.nutrition.org/content/42/1/127.abstract https://www.ncbi.nlm.nih.gov/pubmed/159772 http://m.jap.physiology.org/content/82/1/49
Veganism causes loss of libido and erectile dysfunction:
https://www.ncbi.nlm.nih.gov/pubmed/21353476
Children who are raised on strict vegan diets do not grow normally:
https://www.ncbi.nlm.nih.gov/pubmed/4067152 https://www.ncbi.nlm.nih.gov/pubmed/8005079
Children develop rickets after prolonged periods of strict vegetarian diets:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1874810/pdf/canmedaj01383-0052.pdf
"There are some links between vegetarians and lower birthweight and earlier labour"
https://www.ncbi.nlm.nih.gov/pubmed/7788369
Effects of vitamin B12 and folate deficiency on brain development in children:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3137939/
"Particular attention should be paid to adequate protein intake and sources of essential fatty acids, iron, zinc, calcium, and vitamins B12 and D. Supplementation may be required in cases of strict vegetarian diets with no intake of any animal products."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2912628/
These next five are case studies:
Cerebral atrophy in a vitamin B12-deficient infant of a vegetarian mother:
https://www.ncbi.nlm.nih.gov/pubmed/25076673
Severe megaloblastic anemia in child breast fed by a vegetarian mother:
https://www.ncbi.nlm.nih.gov/pubmed/8442642
Consequences of exclusive breast-feeding in vegan mother newborn - case report:
https://www.ncbi.nlm.nih.gov/pubmed/19748244
Nutritional vitamin B12 deficiency in a breast-fed infant of a vegan-diet mother:
https://www.ncbi.nlm.nih.gov/pubmed/3948463
"We report the case of a 7 month-old girl that presented with acute anemia, generalized muscular hypotonia and failure to thrive. Laboratory evaluation revealed cobalamin deficiency, due to a vegan diet of the mother."