Context: For fortification, however, a 2003 review recommended zinc oxide in cereals as cheap, stable, and as easily absorbed as more expensive forms. A 2005 study found that various compounds of zinc, including oxide and sulfate, did not show statistically significant differences in absorption when added as fortificants to maize tortillas. A 1987 study found that zinc picolinate was better absorbed than zinc gluconate or zinc citrate. However, a study published in 2008 determined that zinc glycinate is the best absorbed of the four dietary supplement types available.

Question: Zinc oxide is used to fortify what product?
Answer: cereals

Question: In what product did  various compounds of zinc show little difference in absorption?
Answer: maize tortillas

Question: What compound is better absorbed than zinc gluconate?
Answer: zinc picolinate

Question: What is the best absorbed dietary zinc compound?
Answer: zinc glycinate

Question: What product is zinc oxide used to taint?
Answer: Unanswerable

Question: What product did various compounds of zinc show massive differences in absorption?
Answer: Unanswerable

Question: What compound is the same as zinc gluconate in being absorbed?
Answer: Unanswerable

Question: What is the only absorbed dietary zinc compound?
Answer: Unanswerable

Question: What year had the only study regarding zinc compounds?
Answer: Unanswerable