One fourth of the vegetarians and 80% of the vegans suffer from iodine deficiency (iodine value below 100 microg/l) compared to 9% in the persons on a mixed nutrition.”https://www.ncbi.nlm.nih.gov/pubmed/21613354
Fatigue, Feeling Cold, Constipation, Hair Loss, Brittle Nails, and Irregular Periods (or, iodine deficiency causing thyroid dysfunction)https://www.ncbi.nlm.nih.gov/pubmed/12748410
Vegetarians have a reduced skeletal muscle carnitine transport capacityhttps://www.ncbi.nlm.nih.gov/pubmed/21753065
Eicosapentaenoic and docosapentaenoic acids are the principal products of alpha-linoleic acid metabolism in young menhttps://www.ncbi.nlm.nih.gov/pubmed/12323085
Why New Ex-Vegans’ Consumption of Fish/Eggs Helps Them to Feel Better (or, Omega Fatty Acid Imbalance)https://www.ncbi.nlm.nih.gov/pubmed/16087975
Hypogonadism and erectile dysfunction associated with soy product consumptionhttps://www.ncbi.nlm.nih.gov/pubmed/21353476
“Endurance performance time was higher for six and lower for two after the mixed diet compared with the vegetarian diet.”https://www.ncbi.nlm.nih.gov/pubmed/159772Don't go vegan.