Bioavailability

When a substance, such as a drug or a supplement, enters your system, the portion of the total substance that is introduced and can actually create a response determines the bioavailability of that substance. The bioavailability of a substance may fluctuate, depending on the route of administration. The administration intravenous, or a direct line into the bloodstream, is typically considered 100% bioavailable, as all of the substance will reach the target cells. In oral routes of administration, also known as when you take a pill, the amount of drug or supplement you receive depends on many factors, including your diet and your personal metabolism.

Bioavailability has become a new and emerging science in recent decades. Many researchers have become concerned about the marketing of foods and supplements. Many producers claim that their foods or nutritional supplements contain certain nutrients. However, the science behind how these nutrients are absorbed into our system is very different. For example, milk claims to have large quantities of calcium. Calcium is known to be a component of bone. Therefore, milk producers have claimed the enormous benefits of milk. However, the bioavailability of calcium in milk has never been demonstrated. In fact, researchers are discovering that milk and dairy products tend to draw calcium from bones to correct the acidity they cause in the bloodstream.

Clearly, the bioavailability of calcium in milk is very low. On the other side of the spectrum, spinach also has a lot of calcium. Scientists have found that when spinach is eaten, calcium is not depleted from the bones and can be extracted from spinach. In part, this is due to the large amount of fibre in spinach, which changes the way it moves through the intestines. This allows more calcium and other nutrients to be extracted. The bioavailability of nutrients in plants is generally higher than that of nutrients in animal products. In part, this is because the human body has evolved to be frugivorous, not necessarily frugivorous. omnivorous or carnivore.

Factors influencing bioavailability

Route of administration

All drugs and nutrients must enter the body in some way. One of the biggest hurdles to overcome when creating a drug is understanding how the drug will reach the cells it needs to target. While it was mentioned earlier that the intravenous route is often considered 100% bioavailable, this is not always the case. A drug that has hydrophilic (water-loving) tendencies will find it difficult to cross the cell membranewhich is very hydrophobic. To increase their bioavailability, they often need to be combined with another substance that is hydrophobic, so that they can slip into the cells.

Oral supplements must also comply with this rule. In addition, they must pass through the digestive system and reach the bloodstream. To do this, they must often be designed to withstand acidic pH balances and high temperatures. Once they reach the intestines, they can be absorbed into the bloodstream. But, like all nutrients and the foods we eat, not all of them will reach the bloodstream before we defecate and eliminate the substance from our system. These limitations severely reduce the bioavailability of most orally administered drugs.

Metabolism

Each person’s biochemistry is slightly different, depending on his or her DNA and how it has interacted with the environment throughout your life. Therefore, your body will react differently to each substance. This will also affect the ability of a medicine to enter the body, be absorbed through tissues, and the overall ability of the medicine to affect target cells. Therefore, the bioavailability of any substance is also affected by individual and unique metabolisms.

In addition, beyond your individual metabolism, all bodies go through different phases. When you are full of food, your body actively works to digest it. Your membranes become more active, your stomach and intestines are actively working to move food and their cells are ready to receive materials. In this state, the bioavailability of supplements and medications increases. When fasting, your body is not ready to move materials quickly from the intestines into the bloodstream, which can significantly reduce the bioavailability of many substances.

Type of substance

As discussed in the definition of bioavailability, the type, size, shape and chemical properties of any given substance are of utmost importance. These properties determine whether the molecule will be able to reach the body and will determine how it interacts with the cell. Some substances are less bioavailable than others. This has become remarkably clear in the use of supplements. While nutritional supplements have some bioavailability, the same nutrients found in natural foods are often found to be much more bioavailable. This is often because supplements do not contain fibre and sugars, which are necessary to help nutrients enter the body.