Category Archives: interactions

If iron interferes with your thyroid function or thyroid meds, you might need zinc

After I started taking Armour thyroid to treat hypothyroid symptoms — including that lovely one where your hair feels like there’s an electric current going through it — I quickly realized that the 50 mg of iron I was taking every day for my abysmally low ferritin levels was making things worse. Even if I separated the doses by the requisite four hours or stopped taking the Armour altogether, I got more hypo-T symptoms — low mood, cold, fatigue, and insomnia.

Taking the Armour only fixed the symptoms to a certain point because of the low ferritin (which was at 6 for several years before any so-called health practitioner bothered to call my attention to it), but I couldn’t take iron to get rid of the rest of the symptoms or it would wipe out all the progress I’d made with the Armour. It was, I remember thinking every other day, like trying to get out of a parking spot in San Francisco on a Friday night — back an inch, hit the bumper, turn the wheel, forward an inch, hit the bumper.

Eventually I figured out that iron lowers zinc and a zinc deficiency can affect thyroid function. I took 50 mg of zinc for several months, then a little less for the rest of the year. After a few months, my mood no longer tanked when I ate dairy (oxalates in dairy will bind to zinc and hinder its absorption). It also solved the iron problem.

Sadly, I still couldn’t take as much Armour as I needed because my adrenals were trashed. Luckily, you can now find much better knowledge and guidance for these sorts of conundrums — see the Stop the Thyroid Madness website to start.

After 18 months on Armour I got sick of the whole thing and started calling acupuncturists all over the Eastern seaboard looking for someone with hardcore-enough training to do medical acupuncture on the thyroid. To my surprise I found someone 30 minutes away. After nine weeks and maybe 14 sessions with him, my test results came back within the newly revised, more accurate normal lab ranges. I stopped the Armour and haven’t felt any hypo-T symptoms since, knock on wood. My low zinc symptoms show up occasionally but they are unmistakably different from the lawdy!-my-thyroid symptoms — mostly low mood and $#@! irritability.

Vitamin C antagonists can raise histamine levels ????

Update 11/17/14: I am no longer sure about this. I don’t know enough about how these nutrients interact re: histamine.

Like many people with a tendency towards high histamine, I’ve discovered that vitamin C can lower it to some extent, which is why it’s so famously used for colds. I’ve also found that supplementing with C’s cofactors can raise my histamine by competing with C. High doses of these nutrients, or long-term use of not-so-high doses, will eventually bring on that spacy, can’t-do-crap feeling. As I’ve explained elsewhere, most nutrients that interact with each other are cofactors at low doses — they work to increase the efficiency of each other — but at high doses they become antagonists and start competing for absorption.

I’ve had this experience with the following supplements:

  • selenium
  • folate in the form of methylfolate
  • iron
  • amino acids

Reasons you might be running low on vitamin C include stress, wonky adrenals, lousy diet, or high copper levels. Apparently vitamin C can also lower cortisol, but since I just learned that 20 minutes ago I cn’t say I have any experience with using C for that. I tend to use calcium and Holy Basil to take the edge off that lovely, high-cortisol jittery, wired feeling.

Histamine aside, Acu-cell has a detailed discussion on how vitamin C interacts with other nutrients. The vitamin C gurus at the Linus Pauling Institute also have several pages on how vitamin C works in the body.

List of my supplement reactions caused by induced deficiencies

As I’ve mentioned in more than a few posts, reactions to supplements are most often NOT caused by poisoning or developing a so-called “tolerance.” Rather, it’s simply that you’ve lowered one of that nutrient’s cofactors (or competitors) too far and induced deficiency symptoms. You can find lists of these “synergists and antagonists/inhibitors” on’s nutrition pages. The site doesn’t supply that info for the B vitamin entries, but B vitamins are mentioned in the cofactor lists of all the other nutrients.

Below is a list of supplement reactions I’ve experienced over the years, with links to related posts where applicable. I did not experience each reaction every time. I have taken many supplements in many courses over the years as I attempted to iron out all the deficiencies caused by 31 years of undiagnosed celiac disease.

I wasted a lot of time figuring all these out because I was laboring under the foolish assumption that my B-complex vitamin was giving me plenty of B vitamins. In fact, B-complex formulations almost always include versions of several vitamins that are in a near-useless form for a significant percentage of people (B1, B2, B6, B12, folic acid). On top of that, there’s the problem that B-complex preparations don’t include anywhere near enough biotin, folate, or B12.

Keeping track of your reactions like this can help you home in on the causes of your health complaints. For example, most of the supplements that worsen my already-bad insomnia are also known to lower both vitamin E and selenium. Perhaps my insomnia is caused by low levels of one or both (they work together). That’s my next experiment.

Nutrient supplement Reaction Induced deficiency cause
B1 (thiamine) low mood, dry skin magnesium
  cracked, dry lips; dry eyes B2
B2 (riboflavin) eye floaters (degrades hyaluronic acid)
B5 (pantothenic acid) insomnia ?
B6 (pyridoxine) headaches B12
B12 (methylcobalamin) fatigue iron
biotin acne B2 or maybe B5
C eye floaters (degrades hyaluronic acid)
calcium asthma-like breathing difficulty, heart laboring vit. K
D3 headaches B1
  asthma-like breathing difficulty vit. K
E headaches, suppressed breathing vit. K? selenium? CoQ10?
folic acid fatigue, spaciness lowered folate, the active form of folic acid, by deactivating methylfolate supplement
methylfolate (a form of folic acid) high histamine C
iron headaches B12
  acne zinc; B2
  vertigo A
  insomnia selenium? E? doesn’t seem to be B2
  worsened hypothyroid symptoms zinc
iodine insomnia selenium? E?
  trouble breathing iron
vit. K insomnia at higher doses E?
magnesium nausea, headaches B12, B6
Omega-3 fatty acids headaches B12? B2?
  insomnia E? (works together with EFAs)

probiotics insomnia selenium? (works together with probiotics: see this article)
selenium high histamine C

On “developing a tolerance” to a supplement

I occasionally encounter people who use the expression “developed a tolerance” to describe that annoying phenomenon in which a supplement works for a while to treat whatever symptoms you’re complaining of, and then stops. Tolerance is more accurately used in the case of prescription drugs or, alas, controlled substances like alcohol or da ganja, and doesn’t really apply to supplements. Although tolerance to drugs and controlled substances builds up for different reasons, they are much different mechanisms than what happens with most supplements such as vitamins, minerals, amino acids, etc.

A common cause of tolerance to a drug is that the drug causes your body to produce less of whatever substance the drug was meant to enhance. This happened to me when I first took clonazepam for insomnia. The drug was originally designed to control seizures, but my doctor at the time prescribed it for my two-hour-a-night sleep problem. For four days I slept NINE HOURS A NIGHT. I’ve never felt so good in my life. Then it stopped working. The doctor said it was a pretty common experience.

Turns out it’s a benzodiazepine (hereafter to be referred to as benzo), a class of drug that affects GABA levels in the brain. GABA is one of the few inhibitory neurotransmitters — it slows everything down, calms an overactive mind, gives you space between your thoughts, plays a big role in sleep. Benzos very quickly convince your body it can produce less GABA, which is why you’re not supposed to take the stuff for more than several weeks. The drug is only active for a few hours, after which you’ve got none of your own GABA to fill in that timing gap, so you take more of the benzo, or take it more often. (Here’s an overview of the different benzo Rx and their relative strengths.)

Many experts feel that supplements of the hormone melatonin have a similar effect. But then you can also find experts who don’t. (FYI in Canada and Europe, hormones are classified as drugs and are not sold over the counter as supplements.)

In the case of supplements that work briefly and then stop, it’s most likely because that supplement helped the uptake of another nutrient (or, more likely, a bunch of them — it’s unlikely that you’re deficient in only one thing) for a while, until it got to the bottom of the barrel.

Every time you take a supplement, a whole bunch of other substances in your body are ushered forth to process it. These are sometimes referred to as cofactors, and each nutrient has its own set, although obviously there’s a lot of overlap. Some of the more famous cofactor relationships are calcium and magnesium, magnesium and vitamin B6, and iron and vitamin C, but it gets even more complicated. Tryptophan needs B6, B2 and iron in order to convert into niacin, and iodine needs enough iron, selenium, and magnesium to do its thang. You can go nuts trying to remember it all.

So either you just happened to take a supplement that was cofactor to something you REALLY needed, or the supplement you took was in fact what you needed, but it used up all its cofactors. The former case is what happened to me with B-complex. The B-complex stopped my leg pain as long as I took it. After two days without it, the pain returned. What finally got rid of it was several months of calcium, which needs the B vitamins for absorption. The B-complex pulled just enough calcium into my bones to make a difference for a few days.

That’s why supplementation is an imperfect, and occasionally downright tedious, way to fix a deficiency — foods have more of the cofactors built in. But our anemic food supply, and the limited number of foods we typically eat, can’t provide enough nutrients to correct a serious deficiency. Or not quickly, anyway.

Don’t take folic acid and methylfolate at the same time

Someone on a B12 deficiency discussion group mentioned that he’d found that if he took folic acid (the synthetic version of the naturally-occurring folate) at the same time as methylfolate (a much more bioavailable supplement of folate; AKA Metafolin), he would start to get folate deficiency symptoms, even though he was supplementing it like a crazy person. I experimented myself and found the same thing — the folic acid cancels out the methylfolate. Folinic acid will do the same.

Because nothing can be easy.

I swear to you I found a PubMed article confirming that folic acid deactivates methylfolate if taken AT THE SAME TIME, but of course I lost it. But if you Google “folic acid blocks” you’ll find all sorts of discussions about it.

This is a separate issue from the problem some people have wherein folic acid will inactivate any folate in their bodies, as well as in all domestic pets within a five-block area, and wreak all kinds of deficiency havoc. We’re just talking supplement interactions here.

What’s annoying is that almost all vitamin B-complex preparations use folic acid, so if you’re taking those you have to schedule accordingly — 1.5 hours in between doses worked for me.

You might note that some experts feel that past a certain amount of supplementation (maybe 800 mcg), folic acid interferes with folate status in everyone to some extent. Here’s a description of why folic acid was marketed even thought it doesn’t work as well — it was patentable, whereas naturally-occurring folate isn’t.

Nutrient interaction symptom to watch out for: eating your young

As I’ve said elsewhere, what most people call supplement side effects are in fact the symptoms of an interaction with another nutrient. You might get headaches from taking vitamin D after a while, not necessarily because you’ve poisoned yourself with too much (although that’s possible) or because the pill has poisonous ingredients (although it might) but because you’ve lowered one of vitamin D’s cofactors too far — in my case, it seems to be thiamine (vitamin B1).

When I figured this out recently, and realized I needed to start taking thiamine, I started investigating what thiamine might interact with. I found this 1942 report excerpt(1) that made me laugh:

“Experiments with animals have recently shown that an excess of vitamin B1 may develop disturbances in lactation and maternal instinct associated with cannibalism. This phenomena was found to be due to a depletion of the manganese supply.”

I don’t have children but if one of my nieces goes missing anytime soon, you’ll know where to start looking.

1. Report excerpt appeared in Canadian Journal of Comparative Medicine, June, 1939, Vol. 111-No. 6. It referred to this study: David Perla and Marta Sandberg, “Metabolic Interdependence of Vitamin B1 and Manganese. Reciprocal Neutralization of Their Toxic Effects.” Proc Soc Exp Biol Med June 1939 41:522—527.

…Which reminds me of another thing I should add to my Lessons learned page: if you can find books on nutrition or orthomolecular medicine published before the mid-1970s, buy them if you can afford them. I’ve got a list of about 10 I’d like, but they’re all over $100.00. After the 1970s the knowledge and research about such interactions tapered off drastically.