1) Good fats (Nemecheck diet... & Nordic Naturals cod liver oil) Brain is fat and water basically. Stay hydrated.
2) Good hormones/neurotransmitters (AKA vitamin D, ideally from sun).
3) Air! Good airway to brain - OSA and even sleep disordered breathing to be addressed.
4) Avoid injury (helmets) & restrict exposure to electromagnetic devices.
Kids are exceptionally sensitive to the above.
5) Oops! Sleep. That's when brains fix themselves. Get enough, especially if you had a stressful day or day filled with new stuff. The reason why babies need more hours than toddlers than kids than teens then adults than the elderly is the fact that novelty needs more time to process.
Oops - forgot some other stuff for brain health under hormones and neurotransmitters...all that oxytocin (try and avoid excessive pitocin - fake oxytocin that is used to decide the day you want your baby born. Just like fake vitamin D it rewires your baby's body to expect the substitute. So when kids feel unloved or disconnected, sometimes spraying some pitocin in their nose is what their hijacked body was craving.) Hopefully we can get some bioidentical hormones at some point. If you have to get pit, smaller doses are helpful. Kids flooded with pit are pitiful.
Okay, so the whole "pitiful" thing was to help you remember it. The truth is they are just socially withdrawn, disconnected and don't ever really feel loved. Mama oxytocin is best! A little nipple stimulation may help start a full-term pregnancy with natural oxytocin. For those who don't know what oxytocin is, it's the hormone of love/connection/bondedness.
For example... if you are super deprived of natural sunlight and you start on vitamin D supplementation... your body is like... yes! This looks close enough... then your skin can start to sage and stuff... maybe get some weird boils and lack of tissue support. That's because you're getting the vitamin D from a pill - AKA your stomach. Vitamin D is created ideally in the skin. It's usually never enough...so other sources like fish oil, mushrooms grown in the sun and even sheep lanolin can help. I don't know why anyone would eat sheep lanolin... but I think my brother told me he took lanolin raw/plain capsule and fell asleep. I'm not sure he did, so I'll have to ask him. I personally prefer what our ancestors ate for sourcing: https://www.consumerlab.com/answers/which-source-of-vitamin-d3-is-better-from-lanolin-in-sheeps-wool-or-from-fish-oil/vitamin-D-source-lanolin/
Basically, most all our health fixes in life are to get back to a few hundred years ago. After all, the genes we have were passed along from people who survived at that time.
In this environment, there is no guaranteed survival for your genetic makeup. New territory here.