Zinc has many different functions in the immune defense and a zinc deficiency increases the risk of infections and diarrhea, which are global causes of disease and mortality. According to a study published in Physiological Reports, being zinc-deficient can also lead to influenza complications such as bacterial pneumonia that is potentially lethal. The authors assume that zinc plays a key role in the body’s defense against respiratory infections, including COVID-19. They write that factors such as unhealthy diets, ageing, alcoholism, intestinal diseases, and various types of medicine can increase the body’s need for zinc.

Most people are unaware of vitamin C’s key role in mental health and mood. According to a large population study that is published in Frontiers in Nutrition, having higher levels of vitamin C in the blood is linked to a lower risk of depression. The official dietary recommendations for vitamin C only focus on preventing the potentially lethal deficiency disease called scurvy, and things like stress, ageing, stimulant use, overweight, infections, and chronic illnesses can increase your need for the nutrient.

In the case of wounds or skin lesions, an active form of vitamin A regulates how stem cells initiate healing processes and produce new skin. This was demonstrated in a study from Rockefeller University that is published in the journal Science. In the future, researchers plan to look closer at how active vitamin A can be used to regulate stem cells as a way of preventing and treating skin cancer.

Vitamin D is important for cellular calcium uptake, bone health, and a number of other functions. There is also a direct link between the widespread vitamin D deficiency problem and brittle bones and osteoporosis among post-menopausal women, according to a large Chinese study that is published in Frontiers in Nutrition. It is important to include magnesium and vitamin K2, as they also contribute to bone health.

Vitamin B3 deserves a lot more attention because of its key role in cellular energy metabolism, the brain and nervous system, our mental health, and our circulatory system. In the cellular powerhouses, we find the derivate form of B3 called NAD, which gives an energy boost. According to a study published in StatPearls, studies suggest that vitamin B3 lowers the risk of Alzheimer’s disease, Parkinson’s disease and other neurological disorders, rheumatoid arthritis, muscle atrophy, and various cancer forms. Many people have an increased need for the nutrient due to factors such as ageing, genetic variations, and poor utilization of the vitamin.

A type of cancer called chronic myeloid leukemia is characterized by an overproduction of white blood cells that can lead to symptoms like fatigue, infections, and other complications. Another characteristic feature of chronic myeloid leukemia is chronic inflammation that contributes to the disease progression. Vitamin C, however, appears to counteract the inflammation, according to a Brazilian in-vitro study that is published in Nutrients.

Patients admitted to the intensive care unit often lack vitamin D, resulting in more complications, prolonged ICU stay, and increased mortality compared with patients who have adequate vitamin D levels in their blood. This was demonstrated in an Iranian study from three hospitals. The study is published in BMJ Nutrition. Many older people and individuals with chronic diseases generally lack vitamin D, which is a problem.

Selenium supports a variety of different selenoproteins and antioxidants that are important for our immune defense, circulatory system, cancer protection, metabolism, gut flora, fertility, nervous system, and general health. This is described in two meta-analyses that are published in Frontiers in Nutrition. The authors mention that there is widespread selenium deficiency in large parts of the world, Europe included, and that this is a public health problem. The big question is how much selenium we need to effectively prevent and treat many chronic illnesses.