For the experimentally inclined

Calcium citrate contains a whole lot of citrate. The formula of calcium citrate is Ca3(C6H5O7)2. Calcium citrate is about 85% citrate. Citric acid can be purchased on Amazon. 4 ounces of food grade citric acid can be purchased on Amazon for $4.99. 4 ounces should be more than enough for the experiment. 600 millgrams of calcium from calcium citrate would have 4000 milligrams of citrate.

A citric acid drink with say 4000 milligrams of citric acid could be drunk 3 or 4 times a day for 3 or 4 days. The drink would only contain water and citric acid. The hypothesis being tested is whether citric acid can befuddle thinking. I am not actually recommending anyone do this experiment but as I stated for the experimentally inclined.

Citric acid should increase iron absorption still I think the adverse effects of citric acid are due to an iron interaction with citric acid in the gut which makes iron unavailable in the gut with very significant negative effects. Iron chelated to citric acid in the gut is not bioavailable in the gut. Iron must be available in the gut as well as systematically. Enhancers of iron absorption can have negative effects on iron metabolism in the gut.

In defense of a calcium citrate calcium supplement but not Mountain Dew the citrate in calcium citrate could largely be be chelated to calcium rather than to iron.

How are Mountain Dew focus groups actually run? Do individuals running the focus groups give indivduals in the focus groups Mountain Dew to drink then riff in ads on postive reactions to Mountain Dew and the individuals who gave those postive reactions?

A proposed experiment

Tea very significantly decreases iron absorption as tannins in tea form insoluble complexes with iron. Iron in iron/tannin-complexes would also not be bioavailable in the gut. Still individuals who drink tea can have normal iron levels. The question is whether blood measures of iron status are a complete picture of iron status. In the proposed experiment rats would be given tea by gavage. Levels of tea given by gavage would not be levels that would cause anemia. What would be tested is the status of aconitase 1 in the gut and the effect of the tea on the citric acid cycle in the gut. Aconitase 1 is regulated by iron levels where with high levels of iron aconitase 1 acts as an aconitase but with low levels of iron aconitase 1 switches to IRP1 which regulates iron regulated proteins. Levels in the gut of citrate synthase, isocitric dehydrogenase and succinate dehydrogenase would would also be tested as iron positively affects these enzymes also. Blood levels of iron would also be tested. The hypothesis is that the effect of tea on the gut in terms of aconitase 1 and other enzymes in the citric acid cycle will be more pronounced than blood levels of iron would indicate.