The NY Times has a "Room for Debate" article on: Is Avoiding Gluten a 
Risky Fad or a Healthy Diet?
http://www.nytimes.com/roomfordebate/2014/02/20/is-avoiding-gluten-a-risky-fad-or-a-healthy-diet

Peter Green is worried that gluten-free grains aren't fortified with 
B vitamins and people should consult with a dietitian. I submitted 
the following comment:


Flours are fortified because they are nutritionally weak foods. There 
is nothing in any grain that isn't more available in other foods. One 
is much better off sticking to nutritionally dense foods and forgoing 
all grains.

You mention B vitamins. If one ate a grain only diet you certainly 
would need to fortify. But the B vitamins are plentiful in a variety 
of foods, which should be part of a person's diet. I made a list for you:

B1 - fish, meat, pistachio nuts, Brazil nuts, dried pecans, raisins, 
green leafy vegetables
B2 - almonds, beef, lamb, oily fish, eggs, pork, mushrooms, spinach
B3 - fish, chicken, turkey, pork, liver, mushrooms, avocado
B5 - mushrooms, oily fish, avocados, eggs, pork, beef, veal, chicken, 
turkey, sweet potato
B6 - pistachio nuts, fish, turkey, chicken, pork, dried fruit, beef, 
bananas, avocados, spinach
B7 - vegetables, fruits, nuts, meat, fish, eggs
B9 - spinach, asparagus, lettuce, avocado, broccoli, tropical fruits
B12 - shellfish, liver, fish, crustaceans, beef, eggs

Note the importance of eating animal foods. Humans did not evolve as 
vegetarians. It is a modern diet based on ethical considerations. If 
one is following such a contrived diet, then they may need the help 
of a dietitian.