|Nutrient||Role in brain function||Main food sources|
|DHA, EPA and phospholipids (PL)||DHA is abundant in the brain. DHA and EPA are components of different PL in synaptic cell membranes. Involved in membrane fluidity and function [48, 103].||
DHA and EPA: oily fish.|
PL: soya, rapeseed, sunflower, eggs, milk.
|Choline||Component of PL. Precursor of neurotransmitter acetylcholine. Modulates neuronal membrane formation.||Meat, dairy products, grains, eggs and fish.|
|Uridine||Constituent of nucleotides, nucleic acids, precursor of brain phosphatidylcholine in membranes [104, 105].||Ribonucleic acid form in foods not bioavailable. As uridine monophosphate in human milk. De-novo synthesis to meet requirements.|
|Cholesterol||Essential component of neuronal membranes , involved in signalling, synaptic plasticity, learning and memory . Also converted to bioactive oxysterols and vitamin D ||Eggs and fat containing foods.|
|Vitamin D||Neuro-steroid, modulates neurotransmission. Helps maintain calcium balance and signalling. Contributes to synaptic plasticity [82, 83].||Limited dietary sources; mainly oily fish, egg, fortified foods.|
|Vitamins A, C and E, selenium, zinc||
Critical role as antioxidants in the brain.|
Zinc also has a role as a neurosecretory product in the synaptic vesicles of specific neurons .
Vitamin A: offal, dairy products, eggs, carrots and dark green leafy vegetables.|
Vitamin C: fruits and vegetables
Vitamin E: nuts, seeds, oily fish, egg yolk and whole grain cereals.
Selenium: meat, fish, legumes, grains (variable content in soil).
Zinc: meat, legumes, eggs, fish, grains.
|Calcium||Important intra-cellular brain messenger  required for synaptic plasticity and secretion of neurotransmitters.||Dairy products.|
|Magnesium||Co-factor in multiple enzyme reactions and regulates N-methyl-D-aspartate receptors. Role in release of neuropeptides in the brain .||Nuts, whole grains, fish, seafood, several vegetables.|
|Iron||Important in oxygen transport for optimal cognitive function.||Meat, fish, cereals, legumes, nuts, egg yolks, some vegetables, potatoes and fortified foods.|
|Vitamins B6, B12 and folate||
Vitamin B6: neurotransmitter synthesis.|
Vitamin B12 and folate: important for oxygen transport for optimal cognitive function. Vitamin B12 is involved in myelin synthesis.
Vitamin B6: grains, legumes, nuts, seeds, potatoes, meat and fish.|
Vitamin B12: meat (especially offal), fish, dairy products, eggs.
Folate: dark green leafy vegetables, legumes, fruits and fortified cereals.
|Iodine||Constituent of thyroid hormones. Important in foetal brain development.||Fish, dairy products, eggs and iodized salt.|