A Guide to Macro Immune Health for Athletes (Part 2)

Sponsored Klean Athlete Heather Bansley hydrating in the gym.

The first article in this three-part series outlined the current macronutrient guidelines for carbs, proteins, fats, and fluids that have been shown to fortify and strengthen the immune system. Part two will take a look at the little guys (aka the micronutrients) who discreetly but impressively support the optimal functioning of this intricate system.

Klean Micronutrient Immune Health Guidelines

Infographic showing details of each macro nutrient.


Vitamin D

For quite some time, it has been well-known that ample vitamin D status is essential for the maintenance of optimal bone health, but recent research has identified vitamin D as a multitasking superstar directly involved in immune cell function and skeletal muscle growth.

Translation for athletes: extra support for the circulatory and respiratory systems so they can consistently work all-out.

Unfortunately, vitamin D deficiency is widespread among the general population and athletes worldwide.

This profound deficiency relates to limited dietary vitamin D sources and the fact that skin exposure to sunlight accounts for 90% of a person’s annual source of vitamin D. This is why deficiencies are especially common in athletes that primarily exercise indoors.

Other factors that can lead to compromised vitamin D status include regular use of sunscreen, darker skin pigmentation, greater body fat levels and ageing.

How to Increase Your Vitamin D Intake:

You can help to increase your intake of vitamin D through your diet, by incorporating foods high in vitamin D including:

  • Cold water fish such as mackerel, tuna, salmon, sardines and herring
  • Vitamin-D fortified low-fat milk
  • Whole grain cereals
  • Egg yolks
  • Cheese

If these foods are not part of your regular routine, Klean-D is a viable, convenient and highly absorbable option.

Choose between 1,000 IU and 5,000 IU options. The 1,000 IU dosage, although higher than the RDA, is recommended by most health authorities for proper maintenance of vitamin D status, especially from autumn to spring. The higher dosage, 5,000 IU, is designed to provide targeted support for athletes who have a history of deficiency, train indoors or receive limited exposure to natural sunlight.


Antioxidants such as beta-carotene, vitamin C and E, and phytochemicals are known for their ability to scavenge free radicals. Intense and/or long-duration training accelerates free radical production, which can lead to immune, muscle, brain and other cell damage, and result in subsequent performance decline.

A review of multiple studies revealed that heavy exercisers demonstrated support for upper respiratory health when they consumed between 250-1,000 mg of vitamin C daily.

How to Increase Your Antioxidant Intake:

To amplify an athlete’s antioxidant game, plenty of colourful fruits and vegetables, and healthy oils such as olive and canola, should be part of the daily schedule.

If you find as an athlete you tend to come up short in the produce department, Klean Antioxidant can be included daily. Favourably, the antioxidants in this nutritional supplement are coming from the Maqui berry, amongst other sources.

For optimal effectiveness, athletes should consume Klean-C during travel and heavy training to squelch free radicals, but limit intake to less than 1,000 mg/day, since it’s unclear whether long-term, high-dose antioxidant supplementation blunts some of the favourable adaptations to training.

Probiotics and Prebiotics

Another area of interest in the nutritional supplement arena for athletes is probiotics. These live microorganisms, when ingested regularly in appropriate dosages, are thought to confer numerous health benefits, including immune support, by temporarily modifying gut-dwelling bacteria known as the microbiota.

Probiotics can support immune health by fortifying the intestinal barrier. As these live microbes metabolise foodstuff, they produce by-products that maintain healthy colon cell function.

What’s more, the beneficial effects of probiotics go beyond the gut, and recent research on the effects of these noble warriors on an athlete’s overall immune and gut health is downright promising.

How to Increase Your Probiotic Intake:

Choose fermented, probiotic-rich foods that naturally contain probiotics or have added probiotics such as:

  • Yoghurt with live active yoghurt cultures
  • Kefir
  • Kombucha
  • Sauerkraut
  • Pickles
  • Miso
  • Tempeh
  • Kimchi
  • Sourdough bread
  • Certain cheeses such as gouda and cheddar

Pair these foods with probiotic fertiliser known as prebiotics. Prebiotics are non-digestible carbohydrates such as apples, asparagus, bananas, onions, garlic, dandelion greens, leeks, and jicama and chicory roots, that are fermented by beneficial bacteria in your gut.

If these foods aren’t at the top of your list, you might want to take Klean Probiotic daily. Klean Probiotic capsules provide 15 billion CFUs of probiotic strains from the lactobacillus and bifidobacterium genera, mixed in a base of prebiotic fructooligosaccharides. These special acid-resistant capsules bypass the stomach and break down in the small intestinal fluid to allow targeted release in the intestinal tract.

Patience is a virtue when it comes to these microbes!! It can take a few months to notice a health benefit.


It’s estimated that up to 90% of endurance athletes do not receive adequate amounts of zinc, which may be due to low-calorie and low-protein diets that are short on meat and high on carbs.

Zinc is known for its antioxidant and immune-supportive properties, and it’s critical for exercise recovery since it is involved in protein synthesis and tissue repair.

How to Increase Your Zinc Intake:

Beef, pork and chicken are not only packed with protein but are also loaded with the mighty mineral zinc. For lean, nutrient-dense cuts, choose 90% lean beef, pork tenderloin and boneless chicken breasts. Oysters, crab and lobster are other options.

If you follow a plant-based diet, plenty of legumes, whole grains, nuts and seeds, fortified breakfast cereals, mushrooms and kale should be prioritised.

As an athlete, you should always have zinc lozenges on hand so you can take a couple when you feel your intake of protein is inadequate.

A Final Word…

Cultivating an immune fortress will allow athletes to maintain good health status in order to complete their training schedule and be optimally prepared for competition. The perfect combination of macronutrients, micronutrients and various nutritional supplements can act as scaffolding for an athlete’s immune fortress.

Each athlete should invest some time in striving to identify the ideal nutrient cocktail that allows them to work at their peak. The third part of this series will provide other lifestyle suggestions that have been shown to further bolster immune operation.

Explore the first instalment in our series guide to nutrient timing for athlete’s here:

A Guide to Macro Immune Health for Athletes (Part 1)


A Guide to Macro Immune Health for Athletes (Part 1)

2021-05-12 09:04:03By Klean Athlete

Created by Karlyn Grimes, MS RD LDN CSSD+
(biography click here)

+Karlyn Grimes, MS, RD, LDN, CSSD is a retained advisor for Klean Athlete.

• Palmowski, J., BoBlau, T.K., Ryl, L., Kruger, K., & Reichel, T. (2019). Managing Immune Health in Sports – A Practical Guide for Athletes and Coaches. German Journal of Sports Medicine, 70(10), 219.

Klean Athlete

Klean Athlete

Klean Athlete