One way to strengthen the immune system is to get enough vitamins, minerals and amino acids. Almost all vitamins have a specific effect on a strong immune system. Our immune system continuously struggles against airborne viruses, carcinogenic particles and bacteria every day. According to research, vitamin and mineral deficiencies increase the need for nutrients in different periods of our lives and cause our immune system to stop functioning properly. Although elderly people, in particular, seem to be at higher risk for these deficiencies, is this an inevitable characteristic of aging? If not, is it the physiological process, food consumption for many years, incorrect nutrition habits, increasing needs or a combination of all these? Unfortunately, there is no clear answer. Although this entire story hasn't been revealed, some nutrients that have an important role in our immune system have been confirmed.

Here are vitamins that strengthen your immune system, increase your body's resistance and their daily intake. Remember that these values are beneficial in boosting your immune system and increasing your quality of life.

Vitamin A Daily intake: 5.000 International Units (IU)

Vitamin B6 Daily intake: 2-50 milligrams (mg)

Vitamin C Daily intake: 60-500 mg

Vitamin D Daily intake: 400 IU

Vitamin E Daily intake: 100-400 IU

Zinc Daily intake: 15 mg

Vitamin A helps body regenerate itself

Vitamin A is indispensable as it is an antioxidant that boosts the immune system. While investigating the effects of vitamin A in children, it was revealed that even a lack of vitamin A in the middle level could negatively affect their respiratory tracts and weaken their immune defenses. Vitamin A deficiency damages the mucosal barrier, which is the natural defense of the respiratory tract; thus, bacteria and viruses benefit from this damage. For example, after an influenza virus attack, a normal person can recover the protective periphery, while an unhealthy cell can easily replace a healthy cell in a person with a vitamin A deficiency, which means a more severe disease and a new second infection.

Foods known to be high in vitamin A are sweet potatoes, carrots and spinach. Support your body in this battle for a quality life and prefer high-nutritional foods in your kitchen.

Vitamin B6 especially good for elderly people

A study was conducted at the Freidman School of Nutrition Science and Policy of Tufts University in Boston. Researchers discovered that the immune system of elderly people is weak since they almost completely remove vitamin B6 from their eating routines. The amount of vitamin B6 needed daily to restore your immune system's power should be more than 2 milligrams. When 50 milligrams of vitamin B6, the maximum intake recommended per day, was given to the participants, it was discovered that the power of the patients' immune system was increased to a higher level than before.

It doesn't matter whether you are young or old. Eat chickpeas, turkey, potatoes and bananas and drink plum juice to increase the amount of vitamin B6. A banana provides 33 percent of your daily intake of B6, while a glass of plum juice provides 28 percent of it.

Vitamin C supports white blood cells

In the medical world, the general consensus is that vitamin C is vital for the production of white blood cells that gather around infected cells and attack, destroy and clean them.

Many fruits and vegetables contain high amounts of vitamin C. For example, 220 grams of orange juice has 200 percent of vitamin C that we need daily. Half a cup of chopped raw red pepper contains 158 percent of what our body needs to take. The real question is: Is the daily amount sufficient for our immune system to work at a high level? Researchers have not yet clarified the answer. However, many nutritionists say that vitamin C intake at least between 500 and 1,000 milligrams a day is important in terms of strengthening the immune system.

I'm sure many of you consume citrus fruits to protect from influenza and similar diseases since they are high in vitamin C. However, citrus fruits have other benefits, such as protecting against cancer, reducing cardiac problems and lowering blood pressure. Citrus fruits, such as oranges, lemons, grapefruits and mandarins, were first grown in south-southeastern Asia and Australia. Now, they are produced around the world, including Turkey, since they are healthy and delicious. Oranges are one of the most consumed citrus fruits. Seventy million tons of oranges, on average, are produced per year in the world. Research shows that citrus fruits prevent the process of cancer as they contain flavonoids and phytochemicals. (Phytochemicals are the common name used to describe bioactive chemical substances found in fruits and vegetables.)

Vitamin D prepares your bones for winter

Canadian researchers have observed that the amount of vitamin D in the bloodstream significantly decreases during autumn and winter months. They found that the amount of vitamin D in one-third of the people that they tested decreased to such a level that it would affect the bone regeneration function of the body. Scientists who did this research in the U.S. reached the same result. Our skin uses solar energy to produce vitamin D. We naturally don't want to go out in cold weather, which means we get less daylight in the winter. While we are out in winter, daylight has a weaker effect on our bodies, and the substances that are effective against daylight in our moisturizers also reduce vitamin D production.

A multivitamin that we take once a day will satisfy our daily intake of vitamin D. Our daily need for vitamin D is 400 IU. Exposure to sunlight for a few minutes per day helps our bodies to restore vitamin D levels. In mineral, calcium and vitamin supplements that some of us consume, the sufficient level of vitamin D also exists.

In people at risk of vitamin D deficiency, commonly, they don't often consume milk products and don't go out much.

Vitamin D increases serotonin, which is important for mental health. It strengthens your immune system, helps your nervous and muscular systems to work properly and provides protection against some kinds of cancer. The easiest way to take advantage of vitamin D is to spend 15 minutes in sunny places several times a week without using any protective cream. If weather conditions do not allow this, get vitamin D from milk, egg yolk or food supplements.

Vitamin E helps fight infections

According to researchers, vitamin E supplements improve the levels of interferon and interleukin that strengthen the immune system. Both of these biochemicals are produced by the immune system to fight against infections.

Vitamin E also helps to prevent oxidative damage in the body. This form of damage is associated with reduced immune response. The killer cells of the immune system also cause a bad outcome when they attack viruses, bacteria and other occupants and perform their duties. This result is the emergence of terrible free roots. Free roots are unstable molecules that steal electrons from healthy molecules to balance themselves and weaken or damage cells. Vitamin E helps these free roots, presenting them their own electrons.

Zinc helps to form immune cells

Like iron, zinc is the first wave of immune warriors. It is very important to have enough troops in this first wave. The slight presence of zinc in the body means that when an invader arrives, the lymphocytes will react much slower and with less force than normal.

Fortunately, serious zinc deficiencies are rare in general. Common zinc deficiencies are usually tolerable. Vegetarians are usually those at greatest risk of zinc deficiency because meat and seafood are foods high in zinc. Keeping your daily zinc intake at 15 milligrams is enough to keep your immune system functioning properly. Indeed, getting this amount isn't very hard. Eighty-five grams of any kind of lean red meat provides nearly 32 percent of your daily zinc intake.