Immune Support Strategies Part One: 3 Top Supplements!
It used to be that this time of year we were only about concerned about not getting sick during cold and flu season. In the last couple of years, staying healthy has taken on a sense of urgency.
My goal here is to provide you with three inexpensive and well-tolerated supplements to help you stay healthy this fall and winter. Next week I’ll be highlighting a simple recipe to keep on hand to boost immune function. The following week, I’ll focus on lifestyle tips for improving immune health. Between the three approaches, my hope is that you and your family stay healthy during this cold and flu season. As usual, my suggestions are evidence-based in order to nudge you into making good decisions.
Questions? Feel free to leave them in the comments below.
Zinc
It is difficult to overstate the importance of zinc to overall immune health, especially for respiratory health. But how exactly does zinc support immune health?
Zinc helps to protect the natural barriers in your nose, the respiratory epithelium. Keeping the nasal tissue strong, helps prevent pathogens from entering the body.
Zinc also is powerfully anti-viral. It works against viruses by preventing them from replicating in the body. As we know, both the seasonal flu and COVID-19 are caused by viruses. Almost ⅓ of the common cold is caused by less dangerous coronaviruses.
Especially in the case of a true zinc deficiency, adding zinc can have a powerful anti-inflammatory effect. The World Health Organization estimates that ⅓ of the world’s population is zinc deficient.
In this country, those most vulnerable to a zinc deficiency include the elderly, and anyone with absorption issues or an autoimmune condition (Wessels, 2020). While the RDA for zinc is only 15 mg a day, the “modern” western diet is notoriously low in zinc.
What else is zinc good for? Glad you asked!
Over 200 enzymes in the body are zinc-dependent
You need zinc to absorb calcium (think bone health!)
Signs of a zinc deficiency may include:
an impaired sense of taste and smell
poor wound healing
sore throat
discoloration to the nails.
Great food sources of zinc include oysters, lean meat, beans, and pumpkin seeds. Oysters by far contain the highest amount of zinc.
Zinc supplementation typically ranges from 5 mg (usually in a lozenge) to a 50 mg capsule. Most people would probably do well taking around 15 mg a day to boost immunity and then bumping their zinc supplementation to 20-30 mg if they get sick.
Caution with zinc:
Do not exceed 50 mg a day for an extended period of time unless your doctor recommends it due to the risk of depressing copper levels
Always take zinc capsules with food to avoid an upset stomach
Excess zinc can cause gut irritation
Excess zinc can cause a metallic taste in the mouth
Food sources of zinc are very unlikely to cause any problems.
Vitamin C
Ever since Linus Pauling popularized vitamin C in the 1970s, it has been a mainstay in immune support protocols. The question is, can vitamin C really prevent viral infections such as the common cold? There is conflicting evidence on this question. At present, the evidence is weak for taking vitamin C to prevent colds. The evidence is much stronger, however, that vitamin C may reduce the duration of cold symptoms, which is also very important (Hemila & Chalker, 2022).
In a recent article out of Italy, scientists agreed that there is a lack of strong evidence supporting the use of vitamin C for the prevention of respiratory infections, “in well-nourished general populations” (Cerullo et al., 2020). Sadly, it’s been a long since most Americans were described as well-nourished.
The article goes on to say that, on the other hand, vitamin C may be helpful for the following populations:
The obese
The elderly
People with diabetes
I would argue that a large percentage of Americans are either malnourished, obese, elderly or diabetic and should therefore consider vitamin C supplementation.
Furthermore, the Italian researchers encourage more research for using high-dose vitamin C intravenously for very sick individuals, including COVID patients. They also point out that vitamin C is inexpensive and well-tolerated by most people (Cerullo et al., 2020).
Personally, I take 500 to 1000 mg of vitamin C daily. If I start to feel under the weather, I switch to powdered vitamin C and take several grams daily for a limited period of time.
What else does vitamin C do?
Helps the body make collagen
Helps make and protect blood vessels
Protects against certain toxins (especially important for smokers)
Who should avoid high-dose vitamin C?
anyone prone to kidney stones
If you have a sensitive stomach
If you are on many commonly prescribed medications including warfarin
Vitamin D
There is an association between vitamin D deficiency and infectious diseases, especially viral ones. Furthermore, among COVID patients with vitamin D levels below 10, daily or weekly supplementation seemed to improve outcomes. Giving vitamin D to critically ill patients shortened hospital stays. There is also evidence that vitamin D may help reduce pro-inflammatory cytokines, the culprits behind dangerous “cytokine storms” (Hadizadeh, 2021).
It is well-known that low levels of vitamin D are associated with poorer outcomes among patients hospitalized with severe COVID. The problem is that vitamin D is also a negative acute phase reactant, a marker that goes down when the body is dealing with inflammation. So we’d expect that vitamin D levels would be low in someone hospitalized with COVID. In my opinion, it might be more interesting to see what their vitamin D levels were a year before getting sick.
In any case, there are also studies that show that giving vitamin D in the hospital can shorten the stay of critically ill patients (Hadizadeh, 2021).
Can vitamin D supplementation prevent school children from getting the flu?
Again, while the studies seem promising, there are also conflicting results. One interesting study involved comparing two groups of Norwegian schoolchildren, one group received vitamin D and the other received a placebo. The number of flu infections was twice as high in the placebo group, suggesting supplementation was worthwhile (Siddiqui et al., 2020).
Vitamin D is perhaps most recognized for its role in bone health. Rickets, the so-called “English Disease” of the Dicken’s novel, A Christmas Carol, involved a link between bone and lung health. Back in the Victorian era, it was common for children to suffer from severe vitamin deficiencies which could lead to both poor bone health and respiratory tract illnesses. Children would work in factories all day long with little sun exposure. And their ability to absorb vitamin D would have also been impaired by the sooty air that blocked UVB rays from the sun (Zhang et al., 2016).
While there are wide-ranging opinions on the subject of vitamin D, I agree with researchers who define optimal levels as between 30-50. Supplementing between 400 and 2000 IU daily should be sufficient for most people. Those with very low levels may need to follow their doctor’s advice and take higher doses for a period of time (Hadizadeh, 2021).
Who should avoid vitamin D supplementation?
Anyone with high levels of serum calcium or phosphorus
Anyone exposed to lead
Kidney disease patients
Disclaimer
The included information is not meant to or should not be used to replace or substitute medical treatment, recommendations, or the advice of your physician or health care provider. The information contained within is strictly for educational purposes and is based on evidence-based nutrition. If you believe you have a medical problem or condition, please contact your physician or healthcare provider.
References
Cerullo, G., Negro, M., Parimbelli, M., Pecoraro, M., Perna, S., Liguori, G., Rondanelli, M., Cena, H., & D'Antona, G. (2020). The Long History of Vitamin C: From Prevention of the Common Cold to Potential Aid in the Treatment of COVID-19. Frontiers in immunology, 11, 574029. https://doi.org/10.3389/fimmu.2020.574029
Hadizadeh, F. (2021) Supplementation with vitamin D in the Covid-19 pandemic. Nutrition Reviews. https://doi.org/10.1093/nutrit/nuaa081
Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews 2013, Issue 1. Art. No.: CD000980. DOI: 10.1002/14651858.CD000980.pub4. Accessed 16 October 2022.
Siddiqui, M., Manansala, J. S., Abdulrahman, H. A., Nasrallah, G. K., Smatti, M. K., Younes, N., Althani, A. A., & Yassine, H. M. (2020). Immune Modulatory Effects of Vitamin D on Viral Infections. Nutrients, 12(9), 2879. https://doi.org/10.3390/nu12092879
Wessels, I., Rolles, B. & Rink, L. (2020) The potential impact of zinc supplementation on COVID-19 pathogenesis. Frontiers in Immunology. https://www.frontiersin.org/articles/10.3389/fimmu.2020.01712/full
Zhang, M., Shen, F., Petryk, A., Tang, J., Chen, X. & Sergi, C (2016) ‘English Disease’ historical notes on rickets, the bone-lung link and the child neglect issuees. Nutrients. https://www.mdpi.com/2072-6643/8/11/722/htm