. Author manuscript; available in PMC: 2016 Nov 17.

Published in final edited form as: Crit Rev Food Sci Nutr. 2016 Nov 17;56(15):2560–2578. doi: 10.1080/10408398.2013.876960

Table 2.

The safety and side effects of the nutrients.

Over-the- counter Nutrient	Effective dose in the clinical trials	Maximum Safe Dose for Long Term Usage*	Side Effects*
ω3 fatty acid	1000mg EPA/day (Jazaveri 2008)	One report says 21g/day	No side effect.
Vitamin C	3000mg/day (Brody 2002)	2000mg/day	No side effect. Large doses of vitamin C can deplete the body’s supply of copper. People with kidney stones or kidney failure and people taking ampicillin, indomethacin, alsalate, or tetracycline should consult their doctor.
Folic acid	500mcg/day (Coppen 2000)	400mcg/day	No side effect.
Vitamin B12	500mcg/day (Almaida 2010)	3000mcg/day	Oral Vitamin B12 has no side effects.
Magnesium	150–300mg/day(Eby 2006)	350mg/day	No side effect is associated with this dose.
Zinc	25mg/day (Siwek 2010)	50mg/day under supervision	High doses of zinc affect the absorption of iron and copper. Zinc should be taken with food to avoid irritating the stomach. People with liver damage or an intestinal disorder should consult their doctor before taking supplementary zinc.