Does taking iron help, or is it actually a risk?
Taking iron clearly helps if you have a deficiency or anaemia, but is pointless and potentially risky if that is not the case. Have your iron levels checked before starting supplements.
Taking iron clearly helps if you have a deficiency or anaemia, but it is pointless and potentially risky if you do not. Have your iron levels measured first.
If you have iron-deficiency anaemia, supplementation is well supported. A large overview of 75 systematic reviews shows that daily iron raises haemoglobin levels and reduces anaemia in infants, children, pregnant women and non-pregnant women. Choose a tablet or drops labelled 'ferrous sulfate': this refers to iron sulfate, the most commonly used form. Pay attention to the elemental iron content in milligrams per tablet. In research, people received up to 200 mg of elemental iron per day for at least 3 to 12 weeks. Always discuss this with your doctor, including the dose. The form you choose, brand or ferrous versus ferric preparation, makes little difference to the outcome.
If you have an iron deficiency without anaemia and feel fatigued, iron may improve that feeling. Four studies involving more than 700 participants found a small to moderate effect on self-reported fatigue. However, your fitness or athletic performance does not improve as a result: maximum oxygen uptake did not improve. Taking iron purely for performance is therefore not worth the money.
Side effects such as nausea and stomach complaints are a real drawback and reduce adherence. In pregnant women with daily complaints, taking iron less frequently may help, but this increases the risk of anaemia around the time of delivery. This is a trade-off to be made with your doctor, not on your own. In kidney disease, premature infants and children on a vegan diet, iron belongs in the hands of a doctor: the dosage and duration depend on the situation and require guidance. If you use thyroid medication or fluoroquinolone antibiotics such as ciprofloxacin, never take iron at the same time: it demonstrably reduces the effectiveness of the medication.
Healthy adults with adequate iron levels gain no benefit from extra iron. Furthermore, too little is still known about the risks of prolonged excessive iron intake.
Based on a Cochrane umbrella review (75 SRs, PMID 34564844), multiple systematic reviews, and European guidelines. The total number of participants across the studies is difficult to determine precisely; the umbrella review covers tens of thousands of participants. The claim regarding fatigue in iron deficiency without anaemia (IDNA) is based on 4 RCTs with 714 participants (PMID 29626044).
Is taking a stack of supplements at the same time dangerous?
Whether a supplement stack is smart or dangerous depends on which substances you combine and whether you also take medicines. Always tell your doctor or pharmacist what you are taking, and be especially careful with St John's wort and goldenseal.
Can you take too much magnesium?
Yes, too much magnesium can be dangerous, although serious toxicity through ordinary supplements is rare in people with healthy kidneys. With kidney problems or the use of intravenous magnesium, medical supervision is genuinely necessary.
Should you take extra copper when taking high doses of zinc?
Anyone who takes more than 25 mg of elemental zinc per day over a prolonged period runs a real risk of copper deficiency, sometimes with serious consequences. Have your blood values checked and always discuss high zinc doses with your doctor.
Does taking vitamin E have any proven benefit?
For the most widely studied application, the heart, vitamin E demonstrably does not work; for skin and fertility the evidence is too thin to say it helps, so there is no clear reason to take it.
Does taking glutathione make sense, or is it broken down in your gut?
Oral glutathione measurably raises levels in blood and cells, so it is not entirely pointless. Whether that rise translates into tangible health benefits has not yet been properly studied.
Why do you still get muscle cramps even though you're taking magnesium?
Research shows that magnesium does little for idiopathic muscle cramps, which fits with what we know about how cramps develop: the problem lies in how nerves control muscles, not in a magnesium deficiency.