Although the flu is up, the cancellation of the March flu vaccine meeting by Robert F. Kennedy Jr. compromises the production of next fall’s flu vaccine. Therefore, maintaining a strong immune system is now more important than ever. Understanding the basics of nutrition science can help you separate facts from popular media hype.

Early humans recognized food as essential for survival. Along with medicinal properties, foods were often thought to have magical powers, and some foods were prohibited or considered unacceptable in some cultures. With the emergence of chemistry and biology, nutrition science could begin to identify individual food nutrients and determine which were essential in regulating the thousands of chemical reactions needed for growth, repair and maintaining health.

More recently, however, vital nutrition concepts have been nearly forgotten on the internet and social media as almost magical powers are attributed to certain “superfoods” while demonizing processed foods.

Here’s what people need to know to maintain their health:

>> Think variety: A person must regularly consume about 40 essential nutrients to maintain their health and normal metabolism. When even a single nutrient is inadequate, health will be negatively impacted; for example, the immune system could be compromised or sleep quality could decline.

It’s important to recognize that the body can use essential nutrients from natural foods, processed and ultra-processed foods, and supplements. For decades, fortifying table salt, milk and flour with various essential nutrients has prevented multiple nutrient deficiencies, especially in children and pregnant women.

To help your body maintain a healthy immune system, focus on eating a wide variety of foods from all food groups. A light sprinkle of iodized salt (not sea salt) and a daily low-dose multivitamin- mineral supplement or a serving of a fortified food, such as fortified cereal, can help you meet those needs and stay healthy.

>> It’s about balance: The current push for a complete whole and plant-based diet will likely result in nutrient inadequacies over time. Our nation’s health has decreased due to the overconsumption of so-called superfoods and the underconsumption of foods containing numerous essential nutrients. For example, iron deficiency now affects about one-third of Americans as beef and other animal products are demonized.

Remember, nutrients generally function in partnership with other nutrients. For example, water, protein, sodium and potassium are necessary to maintain adequate hydration. Too much water alone can cause a severe sodium imbalance.

>> As you age: Although calorie needs decline with decreased physical activity, most nutrient needs do not. Reduced appetite, often considered a part of normal aging, increases the risk of malnutrition and compromised immune function. Maintaining adequate protein is essential and adding a daily low-dose multivitamin-mineral supplement is increasingly important as calories decline.

Joannie Dobbs, Ph.D., C.N.S. and Alan Titchenal, Ph.D., C.N.S. are retired nutrition faculty from the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa.