Supplements for Kids: 7 You Might Not Know They Need

I'm not a doctor. This post is what we do in our house and what I've read, not medical advice. Please talk to your pediatrician before giving your kids any supplement, especially if they take medication or have a health condition.

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Six kids means a lot of little bottles on my kitchen counter. Every morning before school, my kids take their vitamins, and over the years the lineup has changed as I've learned more.

Some of these I started for the obvious reasons, like bones and winter colds. What surprised me was how many of them show up in research about mood. A cranky, irritable kid isn't always just tired. Sometimes a kid is running low on something.

So here are the seven supplements for kids I think more parents should know about: four we use every day, two I reach for when the sniffles start, and one worth asking your doctor to check.

One note before the list: my two youngest, who are 3 and 6, don't take these one by one. They take a kids' multivitamin that has vitamin D, omega-3, B vitamins and magnesium in smaller amounts, sized for little bodies. The older four take them separately.

1. Vitamin D

Vitamin D is the one I'd put first. Kids make it from sunlight, and between school, winter and screens, a lot of them just don't get enough sun.

Most people know it for bones. Fewer know it's been linked to mood. In a University of Michigan study of school kids, children with low vitamin D levels were almost twice as likely to show aggressive, rule-breaking behavior as teenagers. Another large study of children found irritability was one of the most common complaints, and kids low in vitamin D reported more complaints overall. These studies show a link, not proof that vitamin D fixes a bad mood, but it was enough to make me pay attention.

Good to know: the NIH recommends 600 IU a day for kids over one. Vitamin D is stored in the body, so more is not better. The upper limit is 3,000 IU for ages 4 to 8 and 4,000 IU for ages 9 and up, and that includes what's in a multivitamin. A simple blood test can tell you where your kid is.

2. Omega-3 fish oil

Omega-3s, the DHA and EPA in fish oil, are building blocks for the brain. Most kids I know would rather eat almost anything than salmon, so this is one we take as a supplement.

The research on omega-3s and mood is stronger in adults than in kids, so I don't expect a miracle. I think of it as covering a gap in what my kids actually eat. If yours eat fish a couple of times a week, they may not need it.

The ones we use are Nature's Bounty fish oil mini softgels. I like them because they're small. Regular fish oil capsules are big, and a kid who gags on a pill isn't going to take it every day. The label serving is two softgels for adults, so I give my kids one.

Good to know: look for a formula that's tested for purity, and ask your doctor first if your child takes a blood thinner or has a fish allergy.

3. B vitamins

This is the one I most wish I'd known about sooner. B vitamins help the body make the brain chemicals that affect mood, including serotonin and dopamine. Vitamin B6 in particular is needed for the last step of making serotonin, and it's also involved in GABA, the chemical that helps calm the nervous system down.

When B vitamins run low, researchers have linked it to low mood, irritability, tiredness and trouble focusing. For a house with a few kids who feel things big, that caught my attention. I wrote about what else helps in my post on calm down strategies for kids.

Good to know: B vitamins are water soluble, but high doses of B6 over a long time can still cause problems. A kids' B complex at the label dose is the simple route.

4. Magnesium

Magnesium is involved in hundreds of things in the body, including how nerves and muscles relax. It's also one a lot of kids come up short on, since it's in foods like nuts, beans, seeds and leafy greens that don't show up on most kids' plates.

Studies on magnesium and behavior have mostly looked at kids with ADHD. In one, lower magnesium levels went along with more disruptive behavior, and a few small studies found magnesium paired with vitamin B6 helped with restlessness and aggression. It's early research, but magnesium and B6 work together, which is one reason we use both.

Good to know: too much magnesium from supplements can upset a stomach. Gentle forms like magnesium glycinate are easier on kids' tummies than some others.

5. Zinc (the one to ask about)

Zinc supports the immune system and growth, and like vitamin D, it's tied to mood. A review of research on kids found that low zinc and iron are common worldwide and linked to inattention, impulsiveness, picky appetites and mood changes, including sadness and irritability. Cleveland Clinic lists getting sick often, low energy and irritability among the signs of low zinc.

I put zinc in its own category because it's one where more is not better. Too much zinc can cause stomach problems and get in the way of copper. If your kid is irritable, picky and always catching something, ask your pediatrician whether it's worth checking.

What I reach for when the sniffles start

With six kids, a cold never visits just one of them. When I notice one of my older kids, 8 and up, starting to sniffle, I pull out two things: oregano oil softgels and quercetin. In our house, it seems to make the cold shorter. That's my experience, not a promise, and here's what the research actually says.

6. Oregano oil softgels

Oregano oil is concentrated from wild oregano, and its main compound, carvacrol, has shown antibacterial, antiviral and antioxidant activity in lab studies. That's why so many families keep it in the cold-season cabinet.

We use these oregano oil softgels. Like the fish oil, the label serving is two for adults, so I split it and give my kids one.

The honest part: human studies are limited, and there are no real clinical trials in children. It's also strong stuff. I only give it to my kids who are 8 and older, and only as softgels made to be swallowed, never as the liquid essential oil.

Good to know: it can upset the stomach, it can interact with some medications, and it's not for little kids. This is one to talk over with your pediatrician first.

7. Quercetin with bromelain

Quercetin is a plant compound found in apples, onions, berries and tea. In lab studies it works against a number of the viruses that cause colds, and it's also known for calming histamine, which is why people use it for seasonal allergies too.

In a large study of about 1,000 adults, quercetin didn't lower colds for the group as a whole, but a subgroup of fit adults over 40 had fewer sick days and milder symptoms. There isn't good research on quercetin in kids yet, so I keep it to my older ones and only for a few days at a time.

The one we use is quercetin with bromelain. Bromelain is an enzyme from pineapple stems. It's often paired with quercetin because it may help the body absorb it, and bromelain has its own reputation for calming swelling, which is why people use it for stuffy noses and sinus pressure. One small study in young children with sinus infections found those who took bromelain tended to recover a little faster. It's early research, but it's the reason this combination is the one on our shelf.

Good to know: quercetin and bromelain can both interact with some medications, including blood thinners and some antibiotics. Skip bromelain if your child is allergic to pineapple. Ask before you try it.

Food first, then fill the gaps

Supplements aren't a replacement for dinner, sleep or sunshine. I still try to get eggs, fish, beans and fruit into my kids. But with eight people, a budget and a lot of picky eaters, food doesn't always cover everything, and that's where these fill in.

We take ours in the morning before school, as part of our school morning routine. Keeping them in the same spot every day is the only reason anyone remembers.

Supplements for kids at a glance

Every day in our house: vitamin D, omega-3 fish oil, B vitamins, magnesium. The 3- and 6-year-old get all four in a kids' multivitamin.

Worth asking about: zinc, especially for a kid who's irritable, picky and always sick.

At the first sniffle, ages 8 and up: oregano oil softgels and quercetin with bromelain, for a few days.

Dosing: where an adult serving is two pills, I give my kids one. That's what works for us, not a recommendation. Your pediatrician can help you find the right amount for your kids.

Watch for: vitamin D and zinc build up. More is not better. Add up what's in every bottle.

Always: check with your pediatrician first, especially if your child takes medication.

One more time, because it matters: I'm a mom, not a doctor. Nothing here is meant to diagnose, treat or prevent anything. Your pediatrician knows your child, and that's the conversation to have before starting any supplement.