Micronutrient deficiency linked to poor immune response to viruses

A review of current research, conducted by a team of German scientists has concluded that deficiencies in certain micronutrients may contribute to poor immune response in the body and promote the morbidity of certain viral infections.

The researchers examined hundreds of studies conducted into the role of micronutrients in immune response to viral infection and concluded that:

“Micronutrients play a critical role in the coordinated recruitment of innate and adaptive immune responses to viral infections, particularly in the regulation of pro- and anti-inflammatory host responses….inadequate amounts of micronutrients not only weaken the immune system in combating viral infections, but also contribute to the emergence of more virulent strains via alterations of the genetic makeup of the viral genome.”

The micronutrients identified as providing the greatest support to the immune response to viruses  include the following vitamins and minerals:

B Group Vitamins:

B Vitamins are a complex family of micronutrients that work together to support and regulate the immune response as well as suppress proinflammatory cytokines – a signalling molecule that promotes excessive inflammation. It’s known that patients with very high levels of proinflammatory cytokines experience longer than average rates of hospitalisation and generally have a poorer prognosis.

B group vitamins that appear to have the most impact on the immune response include B1, B2, B3, B6, B9 and B12.


For many years zinc deficiency has been linked to poor immunity and is associated with an increased risk of respiratory viral infection. This link has been demonstrated in a number of clinical trials conducted with the elderly residents of care homes.

It’s been shown in studies that proinflammatory cytokines proliferate in people with low levels of zinc. Antibody production and the functioning of NK (natural killer) cells is also impaired when zinc is not present at a sufficient level.

Vitamin D:

In a country like Australia where regular doses of sunshine are almost impossible to avoid, Vitamin D deficiency is uncommon, however it does still occur.

The review found that people deficient in Vitamin D at the time of contracting a virus experienced greater severity of illness and had an increased risk of mortality, particularly those with sepsis and pneumonia. It also found that supplementary doses of vitamin D decreased overall mortality risk and improved the general health of patients. 

One study examined by the reviewers found that critically ill ventilated adults may have better clinical outcomes after being administered high doses of vitamin D3.

Vitamin E:

Several studies have shown that Vitamin E deficiency, particularly in the aged, leads to a decrease in the immune response. And conversely, when Vitamin E supplements are taken by those with a known deficiency, the body’s natural immune response increases. Vitamin E plays a vital role in regulating immature T cells. T cells are important for immunity as they protect the body from pathogens and activate immune cells to fight off infections when they enter the body.


Studies show that when selenium levels are low, the activity of free radicals increases in the body which negatively impacts the important virus-fighting functions of T cells, lymphocytes and NK cells. When selenium is increased to optimal levels the antiviral immune response ramps up, potentially providing resistance to viruses including influenza.

Vitamin C:

Chemical scientist Linus Pauling was the first to suggest that increasing intake of Vitamin C could help treat colds, flus and other respiratory illnesses. His theories were debunked by some in the medical community in the 1980s however there’s now a growing body of evidence that shows Pauling may have been right all along.

The revival of interest in vitamin C therapy to treat infection and inflammation started with trials involving bacterial sepsis and septic shock in critically ill patients. To date, over 300 trials have found that introducing high levels of vitamin C to these patients greatly improved health outcomes and increased survival rates.

Animal studies have also found that optimal vitamin C levels reduces the host’s susceptibility to various bacterial and viral infections.


Copper exhibits potent antiviral properties and a deficiency in the mineral can lead to an increased virulence of a virus and well as a decrease in the presence of T-cells. According top the review’s authors; “It has been suggested that the accessibility of copper in infected cells could be a potentially disrupting factor in the virus life cycle through the distortion of the protein structures on the viral surface. Copper’s antiviral effects may also due to the regulatory roles of copper on certain enzymes, which are critical for the function of various types of immune cells.”

Vitamin A:

Good Vitamin A levels are essential to the health of the lining of the respiratory tract, the skin, the gut, the bladder, the inner ear and the eye. Many studies have shown that vitamin A inhibits viral replication, promotes immune response, and decreases morbidity and mortality of some viral infections.

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