Amidst the rapidly evolving situation on corona virus disease or “COVID-19” and other infectious diseases that threaten our health, one of the best steps to take as precautionary measures is to boost our immune system.

According to Cambridge dictionary, immune system are the cells and tissues in the body that make it able to protect itself against infection. There are three lines of defense in our bodies: 1) The skin, which provides a physical barrier, and hair inside our nose that act as filters against air containing microbes, dust and pollutants; 2) second line of defense is innate immunity that destroys invaders. One of the example is macrophages that enter the body tissues to patrol for pathogens. Second, inflammation brings more white blood cells to the site where the microbes have invaded. Third, fever inhibits bacterial growth and increases the rate of tissue repair during an infection; 3) The third line of defense is specific resistance. This system relies on antigens which are specific substances found in foreign microbes. Most antigens are proteins that serve as the stimulus to produce an immune response, thus the allergic reactions.

The development of our immune system begins in the embryonic stage. During pregnancy, the mother should receive proper nutrition in order for the embryonic tissues to develop well. Adequate nutrition during pregnancy contributes to the normal growth of the fetus, while a baby might be born with low birth weight (<2.5kg) if otherwise.

Infectious and communicable diseases are related to nutrition. If a person suffers from undernutrition, there is a high incidence of infection since the immune system is compromised. Infection, in return, worsens malnutrition and deteriorates health condition.

Optimum nutrition can be an answer to both problems. Balanced nutrition, especially in terms of adequate vitamin, mineral and protein intake, enhances the resistance against infections partnered with regular exercise. Researches show that balanced nutrition subsidizes the immune system. Thus, by eating right, you are helping your body fight and overcome infectious diseases.

Aside from the famous Vitamin C, boost your immune system with the help of these nutrients: protein, vitamin A, zinc, iron and vitamin E.

• Protein plays a role in the body's immune system, especially for healing and recovery. Eat a variety of protein-rich foods including seafood, lean meat, poultry, eggs, beans, and peas, soy products and unsalted nuts and seeds.
• Vitamin A helps regulate the immune system and protect against infections by keeping the skin and tissues in the mouth, stomach, intestines and respiratory system healthy. Get this vitamin from foods such as sweet potatoes, carrots, broccoli, spinach, eggs or commodities fortified with vitamin A such as cooking oil and flour.
• Vitamin C is water-soluble vitamin and an antioxidant that plays an important role in immune function. It helps in the production of white blood cells and functions more effectively in fighting harmful substances such as free radicals. It shortens the wound healing time and improves the absorption of iron. Sources of Vitamin C are guava, orange, lemons, strawberry, papaya, broccoli, and mango. Among these foods, guava has the highest Vitamin C content with 228.3mg per 100 grams of raw guava.
• Zinc is crucial for normal development and function of cells mediating nonspecific immunity such as neutrophils and natural killer cells. Zinc helps wound healing as well. Foods such as whole grains, meat, shellfish, legumes and egg are some of the food sources of zinc.
• Iron is also involved in strengthening immunity. Iron helps increase the number of immune cells particularly white blood cells associated with the generation of a specific response to infection. Common food sources of iron are meat, liver, legumes and dark green leafy vegetables (i.e., malunggay, kamote tops, gabi leaves, petchay, saluyot, alugbati, kangkong).
• Vitamin E is known to be an antioxidant that helps fight free-radicals in our body. Get your Vitamin E from green leafy vegetables, nuts, seeds and avocado.
• Other nutrients such as selenium act as antioxidant to lower oxidative stress on our body while omega-3 fatty acid has an anti-inflammatory effect. Selenium is not produced by our body but it is found commonly in egg, nuts, brown rice, meat and salmon while Omega-3 is found in tuna, salmon, oysters, egg yolk, spinach, and in soybeans.

Lastly, always remember to consume 8-12 glasses of water daily. Water flushes out toxins in the body while keeping us hydrated. Our cells also need water to regenerate.

In the midst of the COVID-19 situation, people resort to panic-buy Vitamin C supplements. However, taking vitamin C supplements in large doses, the excess amount will just be excreted in your urine. It is best that you consume Vitamin C-rich foods such as fruits and vegetables. Eat at least 5 servings of fruits and vegetables each day. Eat a variety of food to get all the nutrients you need. FOOD, not pill. (NO I Vazamija Therese A. Villasi)