Iron Deficiencies are Very Bad and You Should Treat Them

If you are vegan or menstruate regularly, there’s a 10-50% chance you are iron deficient. Excess iron is dangerous so you shouldn’t supplement blindly, but deficiency is easy and cheap to diagnose with a common blood test. If you are deficient, iron supplementation is also easy and cheap and could give you a half standard deviation boost on multiple cognitive metrics (plus any exercise will be more effective).

There are a lot of ways to measure iron and iron-related levels in the body. The two most important are hemoglobin (the protein red blood cells use to carry oxygen) and ferritin (the protein your cells use to store oxygen, but also present in blood). There are some other numbers I’m going to ignore.

Algorithm for treating iron deficiency while minimizing the chance of poisoning yourself:

1. Take a serum ferritin test.
2. If your results show a deficiency (below 20ug/L), increase iron intake through diet or supplements (e.g. Ferrous Bisglycinate Chelate 27mg), taking the default dose once per day, with a meal.
3. If you experience negative effects after taking the pills, stop immediately.
4. If you are experiencing the symptoms of iron poisoning, stop pills and see a doctor now. Iron poisoning is a very big deal, which is why step 1 of this algorithm is “get tested” not “gobble pills”.
5. Retest at 8-12 weeks, ideally at the same lab as before.
6. Continue to retest every 8-12 weeks.
7. If you increase by 20ug from your starting value without noticing any improvements to your cognition or overall energy levels; low ferritin is probably not your bottleneck.
8. If you believe it’s not a problem at all, quit.
9. If you believe it is a problem but another problem is limiting your gains, stay on a maintenance dosage but don’t put more time into managing this.
10. If you’re getting improvements, keep going until those taper off. I personally would exercise caution and investigate the downsides of iron once I reached 80ug/L.
11. Continue to retest and adjust until you’ve found a dose on which your values are stable and healthy.