Vitamin E

Some foods help our bodies.

You can find them in nuts. They are also in seeds. You can find them in peanut butter too.

This food helps keep us well. It helps protect our tiny cells. It works like a shield for cells.

Plants make this food too. It helps plants stay strong in the sun. It also helps seeds grow well.

Most people get enough from food. It is rare to not have enough. This is because many foods have it.

Eating well is a great way to stay healthy!

Vitamin E is a group of eight compounds.

These include four tocopherols and four tocotrienols. These are essential nutrients for humans. This means our bodies need them to stay well.

Vitamin E acts as an antioxidant. An antioxidant is a helper that protects cells.

It works by giving a hydrogen atom to free radicals. Free radicals can damage cell membranes. Vitamin E stops this damage. It can even be recycled by other helpers like vitamin C.

You can find vitamin E in many foods. It is in seeds, nuts, and peanut butter. It is also in many oils.

Plants make vitamin E in parts called plastids. It helps plants stay safe from sunlight. It also helps seeds stay fresh. Without it, seed fats might go rancid.

Some people take vitamin E as a supplement. These are often made in a lab. The natural form is called d-alpha-tocopherol. The man-made form is called dl-alpha-tocopherol. The natural form is more potent than the man-made kind.

Vitamin E is a very important group of eight different compounds.

These compounds include four tocopherols and four tocotrienols. Scientists call them vitamers because they all work together as vitamin E. This group is an essential nutrient for humans. This means our bodies must get it from food to stay healthy. Adults usually need between 3 and 15 mg every single day.

Many people get this through seeds, nuts, and peanut butter. You can also find it in many different seed oils.

Vitamin E works as an antioxidant to protect our bodies.

It acts like a tiny shield for our cell membranes. Inside the body, there are things called free radicals. These are reactive molecules that can cause damage to cells. Vitamin E works by giving a hydrogen atom to these radicals. This simple step stops the damage from spreading. Once the vitamin helps, other helpers like vitamin C can recycle it. This allows the vitamin E to go back to work again.

People have been studying this vitamin for a long time.

It was first discovered back in the year 1922. Later, scientists were able to isolate it in 1935. By 1938, they could even make it in a lab. The name comes from Greek words that mean birth and to carry. This is because it was found to be essential for life. It helped fertilized eggs in rats grow into live births. This discovery showed how important the vitamin is for life.

There are many different forms of these molecules.

The four tocopherols are known as alpha, beta, gamma, and delta. The four tocotrienols use these same four names too. They look very similar but have different side chains. For example, tocotrienols have three carbon-carbon double bonds. In the United States, people used many vitamin E supplements around 2002. However, use dropped by over 50% by the year 2006. This happened after studies showed high doses might not always help.

Plants make their own vitamin E in parts called plastids.

It helps them stay safe from the bright sunlight. In leafy green vegetables, the alpha-tocopherol form is most common. Seeds also use it to keep their fats from going rancid. This helps the seeds stay fresh so they can grow. You can find different amounts of it in different foods. For example, olive oil has more alpha-tocopherol than gamma-tocopherol. Almonds also make more when they face heat or drought.

Vitamin E is a vital group of eight related compounds. These molecules are known as tocochromanols. This group includes four tocopherols and four tocotrienols. Scientists classify vitamin E as an essential nutrient for humans. This means the human body requires it to function properly. Most government organizations recommend that adults consume between 3 and 15 mg per day. A 2016 worldwide review found a median dietary intake of 6.2 mg per day.

These compounds function primarily as fat-soluble antioxidants. They work to protect cell membranes from reactive oxygen species. These species are often called free radicals.

The mechanism involves the vitamin donating a hydrogen atom to a radical. This process is possible because the O-H bond in tocopherols is relatively weak. At 323 kJ/mol, this bond is about 10% weaker than most other phenols. By donating the atom, the vitamin stops the radical from causing damage. The resulting tocopheroxyl radical is then recycled. Other antioxidants, such as vitamin C or retinol, help return it to its active form.

All eight vitamers share a specific molecular structure. They all feature a chromane double ring. They also possess a hydrophobic side chain. This side chain allows the molecule to penetrate into biological membranes. The eight forms are divided into two main groups. The first group consists of four tocopherols. The second group consists of four tocotrienols.

The main difference is in their side chains. Tocotrienols have unsaturated side chains with three carbon-carbon double bonds. In contrast, tocopherols have saturated side chains.

Each of the two groups contains four distinct types. These types are named alpha (α), beta (β), gamma (γ), and delta (δ). These names are determined by the number and position of methyl groups on the ring. For example, alpha-tocopherol has three methyl groups at specific sites. Delta-tocopherol has only one methyl group at a specific site.

The tocotrienols follow the same naming pattern. While tocopherols are essential nutrients, tocotrienols are not classified as such by government organizations. Some research suggests tocotrienols might help with inflammation or heart disease, but clinical outcomes are not yet certain.

History shows how our understanding of this nutrient has evolved. Vitamin E was first discovered in 1922. Scientists isolated the substance in 1935. By 1938, the first synthetic version was created. The name "tocopherol" comes from Greek words meaning "birth" and "to bear." This name was chosen because the vitamin was found to be essential for fertilized eggs in rats to result in live births.

In the United States, the use of vitamin E supplements has changed over time. Use of these supplements peaked around the year 2002. However, use declined by more than 50% by 2006. This decline was likely due to meta-analyses of scientific studies. These studies suggested that very high doses might offer no benefit or could even have negative consequences.

While population studies once linked vitamin E to lower rates of cancer or heart disease, placebo-controlled clinical trials using 2,000 mg of alpha-tocopherol did not always show the same results.

Plants synthesize these compounds in their plastids. They use the Shikimate pathway to create the chromanol ring. They use the MEP pathway to create the hydrophobic tail.

Plants use vitamin E for several important reasons. In leaves, alpha-tocopherol protects against damage from ultraviolet sunlight. In seeds, tocochromanols protect lipids from oxidizing and becoming rancid. This helps ensure the seed can successfully germinate. Environmental stress can even change how much vitamin E a plant makes. For instance, drought or heat can increase the levels of tocopherols in almonds and olives.