Why is the Need to Boost Immunity?

 The immune system is incorporated into all physiological systems of the human body and protects it against infections and other external and internal insults

The immune system in humansranges from the immature and developing immune responses in infants and children, through to immune function which is potentially active in adolescents and young adults, followed by a gradual decline in immunity in older people

Age-related changes are are also dependent on lifestyle factors such as diet, environmental factors, and oxidative stress which in some cases can impact immune function.

Therefore, the risk and severity of infections such as the common cold and influenza, pneumonia and diarrheal infections may differ over a period of time.

It has been observed that adequate nutrition consisting of macronutrients and micronutrients is important for the development, maintenance and expression of the immune response.

Investigators have studied a bidirectional interaction among nutrition, infection and immunity. If nutrition is poor, the immune response gets compromised causing infections, and in turn, poor nutritional state may get aggravated by the immune response which is response to an infection.

Moreover, nutritional status of an individual leading to its immune status can also predict the clinical outcome of an infection.

Micronutrients like vitamins A, C, D, E, B2, B6 and B12, have vital roles throughout the immune system that are independent of life phase.

However, their deficiencies have been reported worldwide, causing multiple infection and diseases. This in turn, warrants the need for intake of these vitamins to enhance immune system and fight infections.

 Role of Various Vitamins in Immunity

 Vitamin A

•  Vitamin A is a fat-soluble vitamin which is pivotal for maintaining vision, promoting growth and development, and protecting epithelium and functional integrity of cells of skin, respiratory tract, etc .
• For Healthy pregnancy, tip is to include vitamin a in your diet.
• It is involved in the development of the immune system and plays regulatory roles in immune responses and that’s why has shown beneficial effects in the treatment of various infectious diseases.
• Several researches have demonstrated that crucial immune organs require constant dietary intake to maintain vitamin A concentrations.
• A trial reported that vitamin A supplementation (50,000–200,000 IU every 4–6 months) in children can reduce the incidence of diarrhea and measles by improving their immune responses.
• Vitamin A is one of the vitamins with anti-oxidant potential and is associated with damaged intestinal immune responses and increased death associated with gastrointestinal and respiratory infections
• Moreover, vitamin A or retinoic acid along with retinoic acid receptor-agonists have been successfully used in the management of autoimmune inflammation, such as experimental allergic encephalomyelitis, adjuvant arthritis and experimental nephritis.
• They have also shown its positive effects in treating psoriasis and preventing contact dermatitis in human.
• Good source of this vitamin includes beef liver, sweet potato, lamb liver, kale, etc.

Vitamin C

• It is one of the main immune-booster vitamin
• Being an anti-oxidant vitamin, its deficiency can cause an increased susceptibility to infections such as pneumonia
• Vitamin C is known to shorten the duration of a cold and reduction of the severity of symptoms in children as well as adults
• Studies have observed that when used in combination with zinc, vitamin C supplementation can relieve symptoms such as nasal discharge in common cold
• It may also improve the outcome of pneumonia, malaria and diarrheal infections in children
• Moreover, diet supplemented with vitamin C is associated with lower risk of cancer of the oral cavity, esophagus, stomach, colon, and lung.
• Foods rich in vitamin C include oranges, grapefruits, tangerines, strawberries, bell peppers, spinach, kale and broccoli.
• Therefore, the most prudent approach seems to be one of increasing fruit and vegetable consumption in the diet, so as to utilize maximum potential benefits of antioxidant nutrients in terms of cancer prevention.

Vitamin D

•  Vitamin D stimulates immune responses and aids in fighting against pathogens
• Its deficiency increases the risk of infection and autoimmune diseases such as multiple sclerosis and diabetes
• Studies have reported that deficiency of vitamin D is particularly seen in females followed by older people
• Its inadequacy also increases susceptibility of an individual to respiratory tract infections
• Thus, supplementation with vitamin D can protect against respiratory tract infections and reduce the risk of acute respiratory illness and influenza
• Although Vitamin D is found in eggs, fish, chicken and cod liver oil, the best source of this vitamin is exposure to sunlight. The UV rays induce the body to manufacture Vitamin D from cholesterol present in your body.

Vitamin E

• Vitamin E with anti-oxidant potential is considered powerful for boosting immunity as it enhances immune responses and offer protection against several infectious disease
• It has shown to increase the production of antibodies in response to the hepatitis B and tetanus vaccines
• A study demonstrated that the risk of upper respiratory tract infections, particularly common cold, was significantly lower after vitamin E supplementation
• Rich source of vitamin E is almonds, peanuts, hazelnuts and sunflower seeds.

Vitamins B2, B6 and B 12

•  Vitamin B2 (riboflavin) maintains healthy blood cells, boosts metabolism and is a powerful antioxidant.
• Adequate dietary and supplemental vitamin B2 intake appears to have a protective effect on various medical conditions such as sepsis, ischemia etc.
• It also contributes to the reduction in the risk of some forms of cancer such as colorectal cancer among women.
• Vitamin B6 (pyridoxine) helps in regulating inflammation
• Its deficiency causes abnormally low levels of white blood cells which plays a crucial role in the function of immune system
• In addition, low levels of vitamin B6 also leads to lowered antibody responses
• Vitamin B12 (cobalamin) deficiency leads to depressed immune responses resulting in delayed-type hypersensitivity response
• Good source of vitamin B2 is spinach, almonds, eggs, steak, soya beans.
• Vitamin B6 is richly found in tuna, turkey, pistachios, sweet potato, banana.
• Sardines, salmon, eggs, yogurt, mushrooms are rich in vitamin B12.

 Immunity boosters in current scenario

• Few studies have highlighted the powerful role of anti-oxidant vitamins in preventing infections like Covid-19.
• A diet full of adequate micronutrients can help in boosting immune system which in turn can help an individual fighting against Covid-19
• Investigators suggested that vitamin D deficiency in combination with diseases like hypertension, diabetes, cardiovascular disorders, metabolic syndrome increases the risk of severe Covid-19 events
• Similar findings were observed by another study that revealed, vitamin D supplementation might play a role in the prevention and/or treatment to Covid-19 infection, by modulating the immune response to the virus both in the adult and pediatric population.
• A cohort study in Singapore has also found that the combination of vitamin D, magnesium and vitamin B12 could reduce the rate of progression in older patients with Covid-19.