Glutamine
In human blood, glutamine is the most abundant free amino acid.
Docosahexaenoic acid
DHA is the most abundant omega-3 fatty acid in the brain and retina. DHA comprises 40% of the polyunsaturated fatty acids (PUFAs) in the brain and 60% of the PUFAs in the retina. Five percent of the weight of a neuron's plasma membrane is composed of DHA.