Zinc Supplements: Which are Absorbed Best?
A 2014 study from Switzerland compared the absorption from various forms of zinc supplements (1). Measuring zinc absorption in 15 healthy volunteers, they found the following median absorption rates:
zinc citrate – 61% (range: 57–71)
zinc gluconate – 61% (range: 51–72)
zinc oxide – 50% (range: 41–58)
The lower absorption from zinc oxide was almost entirely due to three participants who absorbed much lower amounts, with two absorbing almost none.
The authors reviewed other studies which indicated that zinc sulfate and zinc acetate might also be absorbed well.
Interestingly, they noted that none of the study subjects were vegan. They didn’t explain why they pointed this out, but it’s good to know that vegans are on their radar.
1. Wegmüller R, Tay F, Zeder C, Brnic M, Hurrell RF. Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide. J Nutr. 2014 Feb;144(2):132-6. | link