In my pediatric nutrition practice, moms often ask: Is it worth it to spend the extra money on organic foods and pricier supplements brands? My opinion is yes. I often witness how children respond to different foods and supplements, to cheaper brands versus brands of supplements with stricter purity standards, to shifting from processed to more whole foods.

CNN recently reported on a study published in the journal Pediatrics about children with ADHD: They found that children with ADHD were twice as likely to have higher levels of a common pesticide than children who did not have ADHD.  In other words, pesticides commonly used on fruits and vegetables may contribute to ADHD prevalence in the US. Are chronic, small pesticide exposures enough to trigger ADHD in a child? Meanwhile, as any parent who has seen success with a Feingold diet knows, food colorings and preservatives of all sorts have long been suspected of triggering hyperactivity or other problems in children – see this list of 9 additives in particular that have been linked to ADHD.

That is one reason why I encourage families to buy organic foods when possible, even though they cost more. Buying locally from a trusted grower is even better – because you can actually visit or talk to that grower if you want, to see if their methods comply with organic guidelines. Another reason is because – back in 1988, when I was in graduate school – I wondered: Do organic foods have better nutrient profiles? It turns out they often do. Grain crops raised organically may have better amino acid profiles – which means that though they may have less total protein than a conventionally raised version, the protein is of better quality and more nutritious. Fruit crops show more vitamin C and antioxidants when raised organically.

Next on the list of much talked-about toxins are heavy metals like lead, mercury, arsenic, or hexavalent chromium. These are ubiquitous in our environment. Mercury now taints many foods we eat, from high fructose corn syrup to fish. One study found that a serving of high fructose corn syrup contained half a microgram of mercury (0.5 micrograms), and estimated a potential daily mercury intake from foods at about 28 micrograms for Americans. Children and teens may eat as many as 7 tablespoons of high fructose corn syrup daily, from soft drinks, condiments, processed foods, candy, and chewable supplements. This can mean a mercury exposure of about 10 micrograms daily, just from high fructose corn syrup.

By comparison, a flu shot contains about 25 micrograms mercury; and, the EPA guidelines suggest we limit mercury exposure to 0.1 microgram per kilogram body weight daily. For a 60 pound child, that means encountering less than 3 micrograms of mercury daily. For a pregnant woman, this may mean no more than 5 micrograms of mercury exposure daily. We haven’t even talked about coal burning power plants – another mercury source – and it’s easy to see that how easy it is to surpass mercury exposure limits, depending on what we eat.

Lately the CDC and American Academy of Pediatrics have had renewed interest in lead screening for children. Over the years, the level of lead in blood deemed acceptable by these agencies has repeatedly dropped – meaning, there is no safe level of exposure to this neurotoxin, second only to mercury on the list of heavy metals with potential for neurotoxic effects. Lead is a common contaminant in supplements. This is an especially big concern for children who have poor iron status, because those children will absorb more lead than kids in healthy iron status. These metals compete for absorption, and lead is readily taken up by the body in lieu of iron, when iron is not adequately situated in cells and tissues that need it. Lead exposures early on can permanently impair IQ and learning ability.

What about arsenic? From chickens and eggs to playground equipment, arsenic has been found in places our kids go and foods they eat. It may contaminate supplements too, along with pesticide residues and a form of chromium called hexavalent chromium, or Cr-6 for short. Chromium in its “trivalent” form is essential to humans – without it, we can’t regulate blood sugar normally. But in the hexavalent form, it’s highly toxic and known carcinogen, as anyone who has seen the movie Erin. A Consumer Labs review of some supplements found hexavalent chromium contaminants.

Just like the food industry, the supplement industry is challenging for the FDA to adequately monitor, and may not have purity guidelines as strict as parents would like. It often falls on the manufacturer to self-impose strong standards for a product’s purity and potency. But you do have the ultimate power, in your wallet. Buy only what you feel is best for your family’s health and well being. Compare purity standards among supplement manufacturers. If you’re not sure, ask for info from the manufacturer. If you’re not satisfied, move on. In Special Needs Kids Go Pharm-Free, I devote a chapter on “Know Before You Buy” to help families understand differences in purity standards for supplements. Now that I’m done giving you the bad news, here’s the good news on what you can do:

1 – Know your growers. Eat organic and locally sourced meats, eggs, dairy, fruits, and vegetables when possible, given your budget. Check LocalHarvest.org for an organic grower near you.

2 – Grow a garden this year. Start planning now for your kitchen garden, whether it’s herbs on your windowsill, cherry tomatoes in patio crocks, or more in a small patch in the yard. Easy crops for beginners are lettuce, pole beans, bell peppers, carrots, or herbs.  You’ll know exactly what you’re eating!

3 – When buying supplements, demand the best. Compare purity standards, which vary based on a manufacturer’s commitment to quality. For example, fish oils should be strictly mercury free; calcium supplements should be rigorously screened for lead and other contaminants; probiotics should guarantee potency; any supplement should be free of pesticide contaminants, and fillers with no function.

4 – And, just because a supplement is costlier, it may not be better. Ask the manufacturer what toxins they screen their products for, and how. Transparency is the key – if you are told this is proprietary, it may be wise to choose another product.