What are the absorption rates of various forms of dietary supplements?

There is currently no unified absorption rate value for all supplements. The actual absorption rate difference between different dosage forms and different active ingredients can be more than 80% - for example, for the same magnesium supplement, the absorption rate of the most common affordable magnesium oxide is only 4% to 10%, while The chelated forms of magnesium citrate and magnesium glycinate can reach 80% to 90%, which is more than 10 times worse. Many people still suffer from insomnia and leg cramps after taking cheap magnesium tablets, but they are relieved soon after switching to chelated magnesium. The core difference is mostly in the absorption rate.

Many people may have heard the saying that "liquid calcium has a three times higher absorption rate than solid calcium." This conclusion has always been controversial. Current clinical controlled experiments show that for healthy adults with normal gastric acid secretion, the absorption rate of ordinary calcium carbonate tablets and liquid calcium is less than 5%. On the contrary, for the elderly with insufficient gastric acid and people who have undergone gastric surgery, liquid or effervescent calcium can be decomposed without consuming too much gastric acid, and the absorption rate can be about 20% higher than that of solid tablets. Talking about absorption rate out of the crowd is actually a promotional routine of the merchants.

When I was helping fitness friends adjust their supplement regimens, I encountered someone who took 1000mg ordinary vitamin C tablets every time and had extremely yellow urine. This was actually because the excess water-soluble vitamin C was not absorbed and was directly excreted in the urine. Later, it was replaced with liposome-encapsulated vitamin C. The yellow urine was much lighter at the same dose. There are currently small-scale human experimental data. In it, the nutrients wrapped in liposomes can avoid partial degradation in the gastrointestinal tract, and the absorption rate is indeed 30% to 45% higher than that of ordinary tablets. However, the problem is that the price of this type of dosage form is also 2 to 3 times more expensive than ordinary tablets. If it is just a daily supplement, ordinary tablets are completely sufficient. If you really have malabsorption or need short-term large-dose supplementation, it is more cost-effective to choose this type of high-end dosage form.

Many people also think that gummy supplements are easy to take and the absorption rate must be high? In fact, on the contrary, a large amount of excipients such as sugar, gelatin, and pectin must be added during the gummy making process. The proportion of active ingredients is inherently low, and some vitamins have been inactivated during high-temperature cooking. The actual active ingredients that can be absorbed by the human body may not be as high as Half of the ordinary tablets. A mother came to me for consultation before, saying that her child had been eating vitamin C gummies for two months, but the physical examination still showed that she was deficient in vitamin C. After checking, I found out that the actual vitamin C content of the gummy she bought was only 30% of the labeled value. In addition, the absorption rate was low, which meant that she felt lonely after eating it.

I would also like to mention that the absorption rate values ​​promoted by many businesses now are mostly measured by in vitro simulation experiments, which are far from the actual absorption rate of the human body. For example, some brands previously promoted that the absorption rate of a certain type of nano-iron can reach 95%, but in fact the human intestinal tract has a self-regulatory mechanism for iron absorption. When the body's iron reserves are sufficient, no matter what form of iron is eaten, the absorption rate will not exceed 15%. No matter how much you supplement, it will be metabolized and excreted, which may increase the burden on the gastrointestinal tract. There is no need to pay IQ tax for the high absorption rate promoted by merchants.

When you really want to choose a supplement, you don’t have to stick to the absorption rate figures of the merchants. Just choose based on your own physical condition. If you have low gastric acid, you should give priority to effervescent, liquid or chelated supplements. If your gastrointestinal function is normal, the cost-effectiveness of ordinary tablets is high enough. If you have special supplement needs, consider dosage forms with more complex technologies such as liposomes and microencapsulation.