Deficiencies in amino acids, zinc, iron, magnesium, omega-3s, and vitamins: Learn what is and isn’t linked to ADHD symptoms.

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As more and more people receive a diagnosis of attention deficit hyperactivity disorder (ADHD), there’s been a significant increase in research into the symptoms and treatments of this condition.

Over 7% of children and 3% of adults worldwide have ADHD.

A lot of research on ADHD focuses on the underdevelopment of the prefrontal cortex, the front part of your brain, which is responsible for your thoughts and behaviors.

Researchers are also exploring whether a lack of vitamins and minerals, such as certain amino acids, may play a role in the symptoms of ADHD.

Over the years, our understanding of these vitamins and minerals has evolved. Current research suggests amino acid supplements are not an effective treatment for ADHD symptoms. However, other supplements may help.

Amino acids are the building blocks of the proteins throughout your body. Proteins make up many different structures and perform numerous essential functions, including:

  • breaking down food
  • growing cells and tissues throughout your body
  • repairing your body’s tissue
  • signaling between neurons in the brain

Amino acids can be categorized into three groups:

  • Essential amino acids. These must come from food. The body can’t make them.
  • Nonessential amino acids. These are what our bodies can produce, even if we don’t get them from food.
  • Conditional amino acids. These are only essential if you’re stressed or sick.

The 9 essential amino acids

Here are the amino acids that your body needs but can’t make by itself, so you need to get them from proteins in your diet.

  • histidine
  • isoleucine
  • leucine
  • lysine
  • methionine
  • phenylalanine
  • threonine
  • tryptophan
  • valine
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You eat amino acids in the form of protein in your diet. When your body breaks down or digests proteins, amino acids are the products that your body then uses.

While you don’t need to eat essential and nonessential amino acids at every meal, consider aiming to get a good balance throughout the course of the day.

Luckily there are lots of food sources to choose from that provide all nine essential amino acids. These are called complete proteins, and they include:

Other plant-based protein sources, like beans, nuts, and brown rice, are considered incomplete protein sources because they don’t contain all nine essential amino acids.

However, as long as your child eats a variety of plant-based protein sources over the course of the day, they’ll likely get good amounts of all nine essential amino acids.

Consider speaking with a healthcare professional if you want to make sure your child is getting all the amino acids they need each day.

Amino acids and neurotransmitters

Some amino acids are precursor molecules that your body makes into neurotransmitters — signal molecules that your nervous system uses to send messages between neurons, or from neurons to muscles. Other amino acids influence cell signaling in other ways.

Serotonin is one such neurotransmitter. It plays a role in mood and is often called the “happy chemical.”

Tryptophan is an amino acid precursor to serotonin. It may help improve mood, according to experts.

The relationships scientists have discovered between amino acids and neurotransmitters in the body have led people to wonder whether taking amino acid supplements might benefit people with ADHD.

The research to date suggests that amino acid deficiencies aren’t linked to ADHD.

Older research suggests that the brains of children with ADHD may have a decreased tendency to transport certain essential amino acids that affect serotonin and other neurotransmitters.

Lysine, tyrosine, glutamine, glycine, and tryptophan were some of the amino acids the research focused on.

But, over time, researchers have done more studies in this field, and the latest results tell a different story.

In 2016, a group of researchers set out to determine whether children with ADHD had less of the amino acids tryptophan, tyrosine, and phenylalanine in their blood or urine.

These are called aromatic amino acids (AAAs). Levels of these AAAs in your body affect the creation of the neurotransmitters serotonin and dopamine.

However, the researchers concluded that there was no difference in the amount of AAA between children with ADHD and those without ADHD.

In 2018, another study looked at the amounts of amino acids in the diets of children and college students with and without ADHD.

It found there was a slight difference in intake among three nonessential amino acids in children, but no difference among college students.

A review of research into dietary interventions and ADHD did not find supporting evidence that amino acid supplements reduced symptoms of the condition.

Over the years, researchers have explored the potential link between ADHD and other nutrients.


Research has shown a strong association between low levels of zinc in blood and hair samples from children and the severity of their ADHD symptoms.

Taking zinc supplements can help normalize the brain waves of a child with ADHD. It may also improve their memory and information processing, and it’s been shown to decrease hyperactivity and impulsivity in children with ADHD.


Modern diets have all but eliminated magnesium, leading some children and adults to become deficient in the mineral. This may be due to a combination of factors, including processed foods and refined grains, as well as fertilizers used in food production.

In 2016, researchers found that 72% of children with ADHD weren’t consuming enough magnesium.

Over the course of 8 weeks, one group of children received 200 milligrams of magnesium per day, along with their regular medication.

Those who took the magnesium supplements experienced improved measures of cognition. They also showed minor side effects from taking the magnesium — primarily diarrhea and minor stomach pain.


Iron is an essential element for the brain, and not receiving enough iron can affect everything from how well you think to your coordination, according to research. It’s not uncommon for people with ADHD to also have an iron deficiency.

Studies have shown that children with an iron deficiency find it more difficult to focus and perform well in school.

Some research has shown that ADHD in children is associated with nutrient deficiencies in zinc, iron, and magnesium, along with other nutrients.

Omega-3 fatty acids

Omega-3 fatty acids are important for a child’s developing brain, according to research. They play an important role in how the brain, central nervous system, and the retina of the eye form and function.

While not all children with ADHD are deficient in omega-3 fatty acids, some are.

Research has shown that, if a child with ADHD doesn’t get enough omega-3 fatty acids in their diet, their cognitive symptoms could improve with supplements.

An analysis of studies from 2014 found that consuming fish oil supplements seemed to be the most promising dietary intervention for ADHD, alongside elimination diets. Fish oil is rich in omega-3 fatty acids.

If you want to know your child’s omega-3 levels, consider asking a healthcare professional for a blood test. Since this isn’t a commonly ordered test, insurance may not cover it. Home tests are available if necessary.

Vitamin B6

Vitamin B6 plays an important role when it comes to ADHD. If you don’t have enough of it, you may feel more irritable and tired. Increasing this essential vitamin will make you feel more alert and decrease your anxiety.

Plus, vitamin B6 helps other important nutrients do their job. It works with magnesium to create a normal level of magnesium in the blood. It also works together with zinc to help the body create serotonin, according to research.

Vitamin D

From what researchers have discovered so far, vitamin D supplements may help decrease symptoms in people living with ADHD.

Over the years, numerous studies have examined the connection between low levels of vitamin D and ADHD. In 2019, a group of researchers reviewed eight different studies, which included over 11,000 children, 2,655 of whom had ADHD.

They found that children with ADHD had significantly lower levels of vitamin D compared to their neurotypical peers.

In a 2016 study, researchers prescribed stimulant medication to all child participants with ADHD, but one group also received 2,000 IU of vitamin D daily.

After 8 weeks, the group that received the vitamin D showed a decrease in ADHD symptoms during the day and evening, while the group without vitamin D only showed a decrease during the day.

Taking a supplement may help your child with ADHD if they’re experiencing a deficiency in that particular amino acid or another nutrient.

Research suggests that taking fish oil supplements may be the most commonly effective dietary treatment for ADHD, alongside elimination diets.

However, current research does not show that taking amino acid supplements helps with ADHD symptoms.

Overall, taking supplements for ADHD may not always be useful.

That’s because, typically, they’re only beneficial if you don’t have enough of the nutrient. Thus, healthcare professionals may ask your child to do a blood test before they recommend supplements.

Can you take too many vitamins?

It’s important to keep in mind that all nutrients have an optimal dose. Taking too much of a nutrient, as well as too little, can have negative health effects.

That’s why it’s always important to speak with a healthcare professional before giving your child supplements, including vitamins.

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If your child has ADHD and you’re considering giving them supplements, consider consulting a doctor first.

If the bloodwork shows nutrient deficiencies, your healthcare professional may recommend adding supplements to your child’s daily routine.

A healthcare professional can assess your child’s current levels and potential risks to make sure the treatment they receive is safe and appropriate for their needs.