Iron is available in dark leafy greens but still is a concern being less bioavailable than from meat. Iron absorbs better when eaten along with vitamin C so a balanced diet ought to prevent anemia but supplements may be considered, particularly for women as their Iron requirements are higher. Note that it is inadvisable to take Iron supplements if you don't need to, conditions like Haemochromatosis can go be asymptomatic and undiagnosed in young adults.

B12 is a major concern for vegans and strict vegetarians, as moderate intake of eggs or dairy is sufficient to prevent deficiency. It is a stored vitamin which vegans are at risk of developing long-term so monitoring B12 blood levels and supplementation may be necessary.

Incomplete proteins are not a problem on a balanced diet (rather than relying on a single staple crop such as corn), any amino acids missing in one plant food source are available in another. Protein should not be a major concern for vegan since all plants contain proteins, even if they are often higher in fibre and starch than fats or protein. However, protein intake may be a concern for growing children, teenagers, or active people (such as athletes) in which case nuts, beans, and legumes are good vegan protein sources. If you have nut allergies or FODMAP intolerance it may be advisable to consider an ovo-lacto vegetarian diet to ensure enough protein intake for these people.

Iron is available in dark leafy greens but still is a concern being less bioavailable than from meat. Iron absorbs better when eaten along with vitamin C so a balanced diet ought to prevent anemia but supplements may be considered, particularly for women as their Iron requirements are higher. Note that it is inadvisable to take Iron supplements if you don't need to, conditions like Haemochromatosis can go be asymptomatic and undiagnosed in young adults.

B12 is a major concern for vegans and strict vegetarians, as moderate intake of eggs or dairy is sufficient to prevent deficiency. It is a stored vitamin which vegans are at risk of developing long-term so monitoring B12 blood levels and supplementation may be necessary.

Incomplete proteins are not a problem on a balanced diet (rather than relying on a single staple crop such as corn), any amino acids missing in one plant food source are available in another. Protein should not be a major concern for adult vegans since all plants contain proteins, even if they are often higher in fibre and starch than fats or protein. However, protein intake may be a concern for growing children, teenagers, or active people (such as athletes) in which case nuts, beans, and legumes are good vegan protein sources. If you have nut allergies or FODMAP intolerance it may be advisable to consider an ovo-lacto vegetarian diet to ensure enough protein intake for these people.