Most nutrients are not only safe in high amounts, they’re necessary — because too many people simply don’t get nearly enough of the essentials from diet alone.

But it’s also possible to get too much of a good thing, and a new study shows one of the risks of going overboard with iron. This essential mineral, so crucial to your health, could actually contribute to Alzheimer’s disease if you get too much.

In a series of experiments, lab rabbits given a high-cholesterol diet saw increases in their levels of iron in the brain. And as the iron built up, so did the amount of amyloid-beta plaques linked to dementia.

Amyloid-beta alone is a huge red flag, but it wasn’t the only dementia risk factor that cropped up. At the same time, a neuron protein called tau began a process called phosphorylation.

I don’t want to get too technical here, but that’s another big warning sign of dementia.

That’s the bad news.

Here’s the good news: When the bunnies were given the same exact treatment we give humans for excess iron — chelation, in this case with a chelating agent called deferiprone — blood levels of both cholesterol and iron fell and the amyloid beta and phosphorylated tau began to disappear.

Brain levels of iron didn’t fall — only levels in the blood, which is to be expected. And apparently, that alone was enough to do the trick.

Now, I treat people — not bunnies. But I test all my patients for excess iron because you don’t have to have floppy ears and a love of carrots to face the risks. Too much iron over time can cause or contribute to any number of conditions, including heart disease and cancer.

And while you’ve probably heard of iron deficiency anemia, most people have never heard of hereditary hemochromatosis — a genetic disorder in which the body stockpiles iron, allowing it to build up to dangerous levels.

It’s a lot more common than you’d think.

Have your holistic doctor check your own levels of iron — and if they’re too high, make like a bunny and seek a treatment that involves regular blood draws.

I’ve diagnosed a number of patients with this condition the past 18 years, and I can’t tell you how grateful they were since it resolved their fatigue and joint pain, both common symptoms of this condition.

It greatly reduced their risk of complications like early heart disease and cancer.

One of the most common mistakes I see people making is that they take iron supplements or multivitamins with iron, thinking it will help their fatigue. This is a mistake. Don’t take iron unless you’ve been diagnosed as being iron deficient via a blood test.

Keep an eye on your eyes — because your peepers just might be the first part of your body to spy dementia coming.

That’s especially true if your eyes are getting an up-close look at retinopathy, an eye condition that often leads to vision loss and even blindness.

It’s bad enough on its own, but now researchers say a new look at data on more than 500 women finds that dementia and retinopathy may come hand-in-hand — or as close to hand-in-hand as brains and eyes can be, anyway.

Researchers say women given annual memory and thinking tests for up to a decade were much more likely to flunk them if they had the eye disease — and that was true even if they had the blood vessel damage in the retina that marks the condition, but didn’t have any actual vision problems yet.

Of course, that blood vessel damage isn’t truly a disease all its own. Retinopathy is usually a warning of something else going on — another condition that could be causing the same type of blood vessel damage in much less visible areas.

Like the brain.

And sure enough, brain scans of the women in the new study revealed that those who had the eye disease also had blood vessel damage inside the brain itself.

Obviously, the answer here isn’t just treating the eyes. It’s finding and treating the underlying condition before it’s too late. Or better yet, avoiding the condition in the first place — and that means taking care of the rest of your body, because one of the leading causes of retinopathy is diabetes.

In fact, the two conditions are so closely linked that diabetic retinopathy is now the leading cause of new blindness among middle-aged Americans — and we know that diabetics are also more likely to suffer from dementia.

You’ve heard of killing two birds with one stone, right? Avoid diabetes, and you’ll likely avoid three diseases (or more) at the same time.

There are plenty of places on the body where you definitely don’t want fat building up.

Hello, gut.

But there’s one place you want as fat as can be, and that’s right inside your skull. Your brain is actually 60 percent fat — and the most critical fats of all when it comes to brain health are the omega-3 fatty acids found in fish oil.

Now, a new study confirms just how important those fats are for your thinker: People with the lowest levels have aging, shrinking brains and problems remembering what they had for breakfast.

Since the most prominent fat in your brain is DHA, the study of 1,575 dementia-free seniors also finds that it’s the most important one for brain health. The 25 percent with the lowest blood levels of DHA had the smallest brain volumes.

And, yes — when it comes to brains, bigger is definitely better.

Younger is better, too. And while you can’t turn back the clock, your brain can get old before its time — and seniors with the lowest DHA levels had brains that seemed two years older, according to the study in Neurology.

That’s what’s going on inside the head.

Out in the real world, seniors with the lowest omega-3 levels did worse on just about every test thrown their way — including tests on visual memory as well as executive functions such as problem-solving, multitasking, and abstract thought.

Along with charging your thinking cap, omega-3 fatty acids can also help slash your risk of heart problems, stroke, macular degeneration, and more. They can even lower your risk of gum disease.

But let’s stick to the brain today.

In addition to those omega-3s, be sure to get plenty of B vitamins. Studies have shown that seniors who get high levels of B6, B12 and folate have bigger brains, better memory, and more overall protection from dementia’s top risk factors.

You can read more about that B vitamin and dementia link right here.

Meats tend to be richest in B vitamins, but the best way to get what your brain needs is with a quality B complex from a trusted vitamin maker.

Similarly, you can get omega-3 fatty acids from a diet rich in fatty fish — but since most people don’t eat nearly enough salmon, herring, and anchovies, add an omega-3 supplement to your shopping list if you’re not taking one already.

For one more way to power up your grey matter, keep reading.

It’s bad enough that up to a third of all dementia patients in nursing homes are given powerful antipsychotic meds despite the fact that they’re not approved for dementia.

But what makes this one far worse — what makes it a crime in my book — is that doctors know these drugs can dramatically boost the risk of death in these patients, and they keep giving them out anyway.

Now, a new look at data on more than 75,000 nursing home patients finds that one antipsychotic drug in particular is even worse than the rest.

Researchers say Haldol — aka haloperidol — can more than double the risk of death in dementia patients, a risk that’s even higher when you realize that’s not compared to a control group of patients who were given no meds at all.

It’s compared to patients given risperidone, part of a class of meds called atypical antipsychotics. And as a class, these meds are known to increase the risk of death in dementia patients by up to a staggering 70 percent.

It’s like one death risk piled on top of another.

The researchers behind the new study claim the “safest” drug is Seroquel, but that doesn’t make it “safe.” None of these drugs are 100% “safe,” and there’s a reason they haven’t been approved for dementia care: They don’t work, either.

There’s no evidence these drugs lead to better outcomes or improved symptoms, but nursing homes rely on them anyway because they’re great for one thing: Silence.

These drugs are used almost as tranquilizers for dementia patients that are simply too much to handle or even patients who complain too much.

Some of the stories I’ve heard on how these meds are used are outrageous, and you can read more about dementia overmedication abuses here.

In reality, even the most hard-to-handle dementia patients don’t need these drugs, because studies have shown there’s a much simpler way to keep them calm and happy.

It starts with giving them a little more attention, care and sympathy. It might sound basic, but caregivers who pay attention can learn which objects and events trigger certain reactions in dementia patients — and then learn to minimize them or avoid them completely.

Combine that approach with a comfortable routine and a calm environment, and you can give dementia patients everything they need without the risks of dangerous and unapproved meds.

Don’t they deserve at least that much?