Is Your Immune System Taking a Holiday? What To Take

Is Your Immunity Onboard for Your Vacation?

Taking a holiday away from your everyday routine shouldn’t mean leaving your supplements at home. Traveling to exotic places can introduce you  to bacteria and viruses you’ve not been exposed to before. Having a well-nourished immune system may improve your experience and outcomes of infections. If you’re heading to a tropical locale for some fun in the sun, here are 3 nutrients you’ll want to get enough of during your vacation: 

Vitamin C: 

Fruit can be a delicious way to get vitamin C. Oranges, mangoes, pineapples, and papaya all contain good amounts of this essential immune nutrient. But if you’re heading south to Mexico, Central America or South America, be aware that eating freshly sliced raw fruits or vegetables in these regions is one of the well-established risk factors for acquiring hepatitis A-- a non-life-threatening, temporary liver infection that presents with flu-like symptoms.  In fact, Stanford Medicine calls hepatitis A “the most frequently occurring vaccine-preventable infection in travelers”.  That’s because hepatitis A is transmitted via the fecal-oral route, typically from ingestion of food or drink that was prepared by incompletely washed hands contaminated with hepatitis A virus. Eating cooked vegetables is safer because the virus is killed at cooking temperatures---but it won’t satisfy your daily vitamin C requirements because vitamin C is destroyed by heating, especially for longer periods of time.  

We suggest using supplemental vitamin C to ensure your daily vitamin C requirements are being met. Vitamin C fights infectious agents in several ways.  It enhances the production and proliferation of both B and T lymphocytes, which are immune cells involved in response to infection. It improves the mobility of phagocytes—the cells that ‘eat’ pathogens and infected tissue.  Additionally, vitamin C is involved in antibody production against pathogens, so that we have immunity to them the next time they come around. Plus, as an antioxidant Vitamin C also regenerates other antioxidants like glutathione and vitamin E—resulting in even greater protection against the oxidative stress caused by the inflammatory response to infection.  Put all these talents together, and you can see how valuable vitamin C is to our immune system.

Vitamin D:

Current indoor and outdoor studies have shown inconsistent results when it comes to wearing sunscreen creams and their effects on blood levels of vitamin D. For this reason, until we get a consensus from the research community, continuing to follow your usual vitamin D supplement regime may be the best way to maintain your vitamin D levels. 

What role does vitamin D play in immunity? It increases the production of defensins and cathelicidin – anti-microbial proteins that provide a natural defence against disease-causing bacteria and viruses. Studies suggest this vital function is impaired by low blood levels of vitamin D, which are associated with an increased incidence of upper and lower respiratory tract infections in all age groups.  

It can be difficult to get enough vitamin D from diet alone. So we suggest taking a vitamin D supplement year-round, even on vacation. This way, you aren’t depending on higher levels of potentially cancer-causing UV radiation to maintain your vitamin D levels. Individuals with vegan diets don’t need to sacrifice their beliefs; they can take a vegan vitamin D formulation.  

Zinc:

Traveling gives you  an opportunity to sample the local cuisine, like eating seafood while vacationing on the seaside. Clams, oysters and mussels are often touted to be among the highest and most bioavailable food sources of the essential mineral, zinc. But as filter-feeders, mollusks tend to accumulate toxic metals like lead, cadmium, arsenic and mercury as well.  Since heavy metals can build up in the tissues, interfering with health in subtle but significant ways, it’s wise to limit consumption of these foods. Alternative sources of zinc include pumpkin seeds and sunflower seeds.

The destination you’re traveling to is likely to expose you to warmer weather.  Deficiency in zinc can occur from excessive sweating---a natural response to exposure to hot weather. That’s why taking a highly bioavailable zinc supplement like zinc glycinate daily while on vacation is a good idea.

What immune functions does zinc fulfil? It’s an essential mineral in the production of all immune cells, like macrophages, neutrophils, T-lymphocytes and natural killer cells. It’s also vital to the complement system that works together with these white blood cells to fight pathogens. Zinc deficiency has long been associated with increased risk of infection by viral, fungal and bacterial infections. 

Supplying your immune system with the nutrients it needs to function optimally is always important. We suggest adding vitamin C, vitamin D and zinc to your daily routine, even when you’re on holidays. This will give your immune system what it needs to be well-nourished every day as well as for any upcoming trips to a tropical locale for some fun in the sun.

Remember, you may be on holidays, but your immune system can’t be. Bon voyage! 

References 

• Aruoma OI, Reilly T, MacLaren D, Halliwell B. Iron, copper and zinc concentrations in human sweat and plasma; the effect of exercise. Clin Chim Acta. 1988;177(1):81-87.  
• Bartley J. Vitamin D, innate immunity and upper respiratory tract infection. J Laryngol Otol. 2010;124(5):465-469.  
• Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients. 2017;9(11):1211. 
• Centers for Disease Control and Prevention.  Skin Cancer: Sun Safety. Retrieved online February 20, 2024. 
• DeRuisseau KC, Cheuvront SN, Haymes EM, Sharp RG. Sweat iron and zinc losses during prolonged exercise. Int J Sport Nutr Exerc Metab. 2002;12(4):428-437.  
• Gorton HC, Jarvis K. The effectiveness of vitamin C in preventing and relieving the symptoms of virus-induced respiratory infections. J Manipulative Physiol Ther. 1999;22(8):530-533. 
• Government of Canada. “Hepatitis A”. Retrieved online February 20 2024. 
• Hemilä H. Vitamin C and Infections. Nutrients. 2017;9(4):339. 
• Lee S, Choi Y, Jeong HS, Lee J, Sung J. Effect of different cooking methods on the content of vitamins and true retention in selected vegetables. Food Sci Biotechnol. 2017;27(2):333-342. Published 2017 Dec 12. 
• Jaishankar M, Tseten T, Anbalagan N, Mathew BB, Beeregowda KN. Toxicity, mechanism and health effects of some heavy metals. Interdiscip Toxicol. 2014;7(2):60-72.
• Neale RE, Khan SR, Lucas RM, Waterhouse M, Whiteman DC, Olsen CM. The effect of sunscreen on vitamin D: a review. Br J Dermatol. 2019;181(5):907-915.