Myth: If a little is good, more must be better
What the evidence says
Usually not. For most nutrients and medicines, benefit levels off once a need is met, while side effects keep rising. In one trial of alpha lipoic acid, three times the dose gave no extra relief but more nausea and dizziness.
Choose your depth
Usually not. For most nutrients and medicines, benefit levels off once a need is met, while side effects keep rising. In one trial of alpha lipoic acid, three times the dose gave no extra relief but more nausea and dizziness.
Choose Detailed for the fuller picture, or Scientific for mechanisms and study data.
Our bodies work within ranges. Once a deficiency is corrected, extra amounts rarely add benefit and can cause harm.
Two examples from trials
- In the SYDNEY 2 trial of alpha lipoic acid for nerve symptoms, 600 mg a day worked as well as 1200 or 1800 mg, while higher doses caused more side effects.
- In the VITAL trial, giving vitamin D to people who were not deficient did not reduce fractures.
Why it matters
Fat-soluble vitamins such as A and D can build up in the body. Minerals such as iron and zinc compete with each other. Herbs at high doses are more likely to cause reactions.
A better rule
The right amount, of the right form, for the right person, for the right length of time.
Dose-response curves for most micronutrients follow a sigmoid relationship with a plateau once tissue saturation is reached, while toxicity follows a separate curve. Tolerable upper intake levels set by bodies such as ICMR-NIN define the highest daily intake unlikely to cause harm.
What we know
- Benefit plateaus once needs are met.
- Side effects generally increase with dose.
What remains uncertain
- Individual differences in requirements.
The evidence
Related ingredients
Sources
- LeBoff MS, Chou SH, Ratliff KA, et al. Supplemental vitamin D and incident fractures in midlife and older adults. N Engl J Med. 2022;387(4):299-309.
- Ziegler D, Ametov A, Barinov A, et al. Oral treatment with alpha-lipoic acid improves symptomatic diabetic polyneuropathy: the SYDNEY 2 trial. Diabetes Care. 2006;29(11):2365-2370.
Last updated 15 October 2026.
This is educational content and does not replace advice from a qualified doctor. If you have symptoms or take medicines, please speak to your doctor before making changes.
