Food-grade citric acid (also sold under the name “sour salt”, usually shelved with spices) is FDA-classified as GRAS. Looking at Amazon, the Spicy World Citric Acid in the 5-pound bag is $19.23 (free shipping for me, since I have Amazon Prime).
At the ~2g of citric acid metabolizing into ~1g of oxaloacetate you suggest, that translates to a price of $0.05 per three grams of oxaloacetate, or three orders of magnitude cheaper than buying a bottle of 30 100-mg capsules for $49.
Food-grade citric acid (also sold under the name “sour salt”, usually shelved with spices) is FDA-classified as GRAS. Looking at Amazon, the Spicy World Citric Acid in the 5-pound bag is $19.23 (free shipping for me, since I have Amazon Prime).
At the ~2g of citric acid metabolizing into ~1g of oxaloacetate you suggest, that translates to a price of $0.05 per three grams of oxaloacetate, or three orders of magnitude cheaper than buying a bottle of 30 100-mg capsules for $49.