• by: Fondazione Valter Longo Onlus Editorial Staff
  • August 20th, 2022


Daily nutrition must provide the immune system with all the nutrients it needs to stay healthy and to carry out normal physiological functions. The energy needs of adult women are different according to the age group and the physical activity performed. The energy needs for 18 to 29-year-old women vary from 1790 kcal to 3550 kcal per day, and for 30 to 59-year-old women vary from 1820 kcal to 3160 kcal per day. Energy needs decrease with age25.

Regarding macronutrient26 intake, fats must be 20-30% of the total energy, in particular the recommended daily allowance of polyunsaturated fatty acids (omega-3) is 0.5 g of EPA (eicosapentaenoic acid) + DHA (docosahexaenoic acid), avoiding higher and prolonged dosages as they can have the opposite effect27. They are considered essential fatty acids because our body needs them to function normally. Nevertheless, it is unable to produce them by itself. The recommended quantity is easily achieved by eating fish twice a week and EVO Oil with each meal (EVO oil is an Extra Virgin Olive oil. It is made from pure and cold-pressed olives). You can replace it with linseed oil, algal oil, and soybean oil with each meal, and with about 20 g (0.7 oz) of nuts per day28.

As for carbohydrates, we recommend an intake of 45-60% preferably from whole grains29.

Although sugars must be less than 15% of the total daily energy30, they must not be totally avoided as they are important in regulating blood sugar levels to support the immune system. In fact, despite the few scientific studies in this regard, it is possible that severe chronic calorie restriction may lead to deficiencies in the immune system, especially in old age31 32.

Regarding proteins, 0.8 g (0.2 oz) are recommended per kg (2.2 lbs) of body weight per day.

It is important to get 25 g (0.8 oz) of fiber per day through the consumption of vegetables, legumes, whole grains, and fruits33.

The micronutrients with the strongest scientific evidence for immune support are vitamin C, vitamin D, and zinc34.

Starting with vitamins, it is recommended to consume foods rich in vitamin C such as peppers, tomatoes, citrus fruits, kiwis, strawberries, red cabbage, broccoli, lettuce, rocket, and currants35. It is important that these foods are eaten raw because vitamin C is thermolabile, which means that it easily lost in the cooking process.

It has been seen that vitamin D deficiency has been associated with an increase in the incidence or mortality from COVID-1936, so it is essential to consume it through the diet and through moderate exposure to sunlight. It is abundant in fish such as herring, horse mackerel, sea bass, anchovies, mackerel, mullet, mushrooms, and eggs37. Vitamin D also plays an important role in improving sleep quality.

Vitamin A is present in the form of retinoic acid in foods such as carrots, spinach, peppers, pumpkin, beets, sweet potatoes, watercress, chicory, celery, persimmons, and apricots, but also in spices like paprika, and in eggs38.

Other vitamins are also useful in supporting and strengthening the immune system, such as 1) vitamin E, found in sunflower seeds, almonds, hazelnuts, avocados, chicory, shrimps, blackberries, chestnuts, extra virgin olive oil, and olives39, 2) B vitamins in fish products such as clams, herring, trout, mackerel, salmon, as well as eggs (vitamin B12); spinach, potatoes, legumes (beans, chickpeas, and peas), fruit (excluding citrus fruits) (vitamin B6); asparagus, beets, fresh broad beans, green beans, artichokes, endive or escarole, cabbage, cauliflower, and fennel (vitamin B9)40.

As far as minerals are concerned, zinc is mainly found in fish, cereals, legumes (beans, lentils, and chickpeas), nuts (almonds, pine nuts, and cashews), seeds (pumpkin, sesame, and sunflower), mushrooms, and cocoa.

Iron, copper, and selenium, with different and very precise mechanisms, also support the immune system.

The iron obtained from the diet is divided into “heme” and “non-heme” iron:

  • The first is present in foods of animal origin and contains a molecule (heme) which, thanks to the iron atom can bind oxygen and transport it to the tissues. The “heme” iron is easily absorbed by the body and is found in liver, horse, and beef red meats, but also in sea bass, clams, anchovies, and other seafood products in general41.


  • “Non-heme” iron, which is not linked to the “heme” group, it must first be reduced by an antioxidant, such as vitamin C (ascorbic acid) in order to be more easily absorbed. Therefore, combining foods that contain “non-heme” iron such as lentils, beans, dried plums, raisins, dried apricots, cashews, and pistachios with other foods rich in vitamin C, such as citrus fruits, kiwis, lemon juice, tomatoes, raw peppers, and rocket/arugula, promotes iron absorption. On the contrary, some substances inhibit the absorption of “non-heme” iron, so consuming the following products simultaneously is not recommended: tea, coffee, chocolate, yogurt, cheeses or foods rich in calcium, and water with a high calcium content.

Copper is found mainly in oysters, nuts, oil seeds, dark chocolate, whole grains, and meat42. Selenium is particularly present in cereals, fish, meat, and dairy products43.

For more information about supplements, physical activity, and sleeping patterns, as well as delicious recipes, download for free the Nutritional and Lifestyle Guidelines for Women for a Stronger Immune System.

Link here


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