New Delhi, Mar 17 (IANSlife): The more nutrient dense foods you can get in daily diet, the better. There are five significantly potent immune-boosting nutrients that will give your body an extra wall of defense.

Renee Grandi, Nutritionist and Naturopath, Chiva-Som shares five immune boosting nutrients:

Zinc

Zinc is a well-loved mineral in the immunity world. It nourishes and supports the innate (first defense) and adaptive immunity (long-term, has memory). Zinc is a cofactor for over 200 enzymatic reactions within the body, with many of these being immune dependent mechanisms.

It supports the thymus gland in adaptive T-cell production/regulation and acts as a free-radical scavenger. We love zinc as it supports against viruses and bacterial pathogens and promotes healthy function and integrity for our white blood cells: macrophages, neutrophils, natural killer cells, T-cells and lymphocytes.

Food Sources: Pumpkin seeds, sunflower seeds, egg yolks, seafood, oysters, beef

Vitamin C

This is probably your go-to nutrient when it comes to immune boosting superstars, and all for the right reasons! Vitamin C (ascorbic acid) is one of the body's most essential antioxidants, and we need constantly replenish it from external sources. Vitamin C has shown to significantly strengthen the body's immunity, particularly during times of stress and infections. White blood cells have high concentrations of vitamin C that are essential to all levels of defense against free radicals, pathogens and inflammation. It helps to upsurge white blood cells (first defense and adaptive) communication, durability and pathogen killing abilities! Vitamin C contains substantial detoxification and anti-inflammatory properties and is a great nutrient to have on hand for viruses, bacterial infections - especially for systemic or respiratory conditions.

Food Sources: Green leafy vegetables, citrus fruits, kiwis, papayas, strawberries, mango, red peppers, and cabbage.

Vitamin A

Vitamin A comes in many different molecular structures, retinyl palmitate is one of the most abundant forms and retinyl esters are found mainly in animal products such as: eggs, liver, fish oils, milk and butter. Plants provide us with the precursors to Vitamin A in a carotenoid form, this proceeds to further biochemical reactions to make Vitamin A.

Vitamin A is excellent for skin and gut integrity, which is our first line of defense from the exterior pathogenic world.

Food Sources: Orange coloured fruits/vegetables and dark green leafy vegetables: papaya, squash, carrots, spinach, broccoli, sweet potatoes, kale, and pumpkin.

Vitamin D

Vitamin D is best sourced from UV sunlight, it is obtained through 2 pathways: activation within the skin and through the diet. If you receive adequate levels of sunlight, usually you would not need to supplement vitamin D. Unfortunately, many of us live in a rather gloomy climates where supplementation is vital. Vitamin D has been shown to significantly regulate immunity and to support auto-immune conditions. This wonderful fat-soluble vitamin also enhances the first defense system mechanisms against pathogens and improve our immune systems; targeting, natural killing and detoxification processes.

Food Sources: Eggs, liver, fatty fish, and butter.

Selenium

Selenium is an essential trace element found in high quantities within immune tissues such as the spleen and lymphatics. It has been shown to regulate innate and adaptive immunity, particularly against virulence of viruses, sometimes these can be harmless but without sufficient selenium, they can mutate into more powerful and detrimental forms.

Selenium can improve response times and increase natural killer production (pretty much helping your immune systems army prep for full force).

Food sources: brazil nuts, alfalfa, organic meats/eggs, onion, garlic and broccoli.

Extra tips for nutrient immune support:

Make a batch of organic bone broth and drink 1 - 2 x cups per day

Add in an extra nutrient dense super green juice (kale, turmeric, ginger, lemon, cucumber and celery)

Ensure you're getting 2L of filtered water per day

Have 1 x source of probiotic rich foods per day (sauerkraut, kimchi, kefir, miso soup or yoghurt), if you think this is difficult to fit in, I would highly recommend taking a good quality probiotic.

Dietary exclusions:

Caffeine

Preservatives, additives and food colourings

Processed foods (think anything in a packet)

Sugar/overconsumption of fruits