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The notion that there are practically no good substitutes for a balanced diet, and that food is the best source of the vitamins and minerals we need, is not a novel one. But in recent years, the message has grown stronger: our bodies prefer natural sources of vitamins and minerals, simply because they are better absorbed that way.

"Supplements are never a substitute for a balanced, healthful diet," affirms Dr. JoAnn Manson, professor of epidemiology at Harvard's T.H. Chan School of Public Health, citing in an article the various medical studies supporting her claim. "And they can be a distraction from healthy lifestyle practices that confer much greater benefits,” adds Manson.

So, does this mean vitamin and mineral supplements aren’t necessary at all? Actually, no. There are several medical conditions that put people at a higher risk of developing nutritional deficiencies, and some diseases can be prevented and treated with certain nutrient supplements. But their consumption should be guided by a medical professional, who can determine who needs what and where to acquire the supplements.

There are also guidelines for specific groups, such as pregnant women. Folic acid is especially important for the healthy development of a fetus, and a deficiency of the vitamin can cause spina bifida, a neurological condition.

Immune System Supplements

Since the announcement of the COVID-19 pandemic and the beginning of lockdowns, our eating habits took center stage. In addition to following best practices for handling and preparing foods at home, grocery shopping safely, and frequent cleaning, we became aware of the role that diet and nutrition play in our immune system.

Nutrition and the immune system, as well as the likelihood of getting sick, are related factors. That’s why people who are malnourished are at a higher risk of contracting viral and bacterial infections.

Conversely, chronic or severe infections can have an impact on the body’s nutritional state. That’s why it’s so important to maintain good eating habits during the COVID-19 pandemic.

The  medical experience with other chronic illnesses, such as hypertension and diabetes, or even HIV and other immunodeficiency disorders, suggests that supplementing a high-quality diet with multivitamins could help reduce the risk of contracting of developing COVID-19.

Products that claim to stimulate or “support” the immune system are generally divided into vitamins and probiotic formulations.

There is some truth to the concept that vitamins can help immunity. They can prevent diseases and other health problems, but only in people suffering from severe malnourishment, a rare condition for the average adult. Consequently, vitamins will do little to help people who are already healthy.

When it comes to probiotics, it’s also true that bacteria and organisms living in the gut can play a role in our health.

But the reality is that there is not enough evidence yet on how to use dietary supplements to treat health issues and alleviate illnesses. At the same time, a daily balanced, complete, and varied diet remains the most important factor in any case. 

What Exactly Is A “Balanced Diet”?

A healthy diet focuses on eating vegetables, fruits, whole grains, legumes, nuts, and seeds. It also includes moderate consumption of fish, poultry, and low-fat dairy, as well as limited quantities of red meat, processed foods and meats, simple carbohydrates, and sugars.

All accompanied by moderate amounts of vegetable oils such as olive oil, canola oil, or soy oil for cooking.

A diet that provides the right amount of calories and supplies the nutrients to cover your protein, complex carbohydrate, healthy fats, and vitamin requirements can help you mainta in an appropriate body weight according to your height and physical build. 

People who have healthy and quality eating habits will have higher protection if they become sick with the novel coronavirus. This is especially true if their diet provides the necessary amounts of minerals and vitamins. These elements help secure the sufficient amount of cells for the immune system and antibodies, essential to the organism’s infection response.

Though there is still much left to learn about the effects of nutrients on COVID-19, there are some previous studies related to specific nutrients and their effects on other viral infections. 

When To Take Vitamin and Mineral Supplements?

Food consumption surveys often show that many people have deficient diets, lacking the amounts of vitamins and minerals recommended by national dietary guidelines. This is sometimes caused by inaccessibility to healthful foods, high costs, or poor eating habits. The situation worsened during the COVID-19 pandemic.

Because of their potential benefits with regards to some viral infections, certain vitamin and mineral supplements could be helpful, especially to older people or people with nutrient deficiencies. It’s always best to get a medical prescription for supplements so as to ensure the right dosage.

Zinc

Zinc is fundamental to an adequate immune response. For example, a review of seven studies demonstrated that 80–92 mg per day of zinc may reduce the length of the common cold by up to 33%, shorten the duration of flu symptoms, and aid in recovery.

The body generally receives enough zinc from a varied diet. Food sources of zinc include chicken, red meats, and fortified breakfast cereals, among others. 

Because it is necessary for immune cell function and cell signaling, a deficiency can lead to a weakened immune response. Zinc supplements stimulate particular immune cells and reduce oxidative stress.

Though people often take zinc by mouth to treat colds, it’s important to note that it can reduce the efficacy of some medicines and bring side effects.

Vitamin C

Vitamin C acts as an antioxidant, limiting inflammation and damage of the tissues associated with the immune response. Some studies have shown that it can significantly lower the incidence of respiratory tract infections. Clinical use on patients in intensive care has yielded good results.

In studies of its effectiveness against viruses that cause the common cold, vitamin C doesn’t appear to make you any less likely to get a cold — but it may help you get over a cold faster and make the symptoms less severe.

It’s easy to meet the vitamin C needs through a diet as long as you eat a variety of fruits and vegetables. For example, a single medium orange provides 77% of the daily value (DV), and 1 cup (160 grams) of cooked broccoli provides 112% of the DV.

Vitamin D

Vitamin D has several important functions. Perhaps the most vital are regulating the absorption of calcium and phosphorus, and facilitating normal immune system function. We get vitamin D from three sources—food, supplements, and sunlight

Few foods contain vitamin D naturally. Because of this, some foods are fortified. This means that vitamin D has been added. Foods that contain vitamin D include salmon, sardines, egg yolk, shrimp, milk (fortified), cereal (fortified), yogurt and orange juice (fortified).

Evidence provided by some clinical studies supports the claim that vitamin D supplements could help decrease acute respiratory tract infections (due to viruses) by 12 to 75%. These studies focused on both the seasonal flu and the influenza pandemic caused by the H1N1 virus in 2009.

The beneficial effect of the supplement was observed in patients of all ages as well as in people with preexisting conditions. For example, some people recovered quicker when they took doses of vitamin D higher than 1,000 IU. The greatest benefits were observed in people that already had a previous vitamin D deficiency.  This should always be discussed with a doctor.

Keep in mind that many multivitamins and multiminerals already contain between 1,000 and 2,000 IU of vitamin D. Read the labels.

Multivitamins/Multiminerals

Multivitamins are supplements that contain many different vitamins and minerals, sometimes alongside other ingredients. As there’s no standard for what constitutes a multivitamin, their nutrient composition varies by brand and product.

Could be beneficial, but they must meet the Recommended Dietary Allowance (RDA) for vitamins and minerals. The RDA is the average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%-98%) healthy people. These values vary by age and sex.

Multivitamins aren’t right for everyone and may even harm some individuals. However, certain populations may benefit from multivitamins, including: Older adults, vegans and vegetarians, and pregnant and breastfeeding women.