How to Boost Your Immune System – What the Science Says

We always advocate aiming to get as many nutrients from your diet as possible, but in some cases, a little supplementation can help. Here’s what we found to have the most compelling evidence for reducing your risk from respiratory viruses.

Vitamin D

• What the science says: In people with Vitamin D levels less than 38 ng/ml, the risk of having an upper respiratory infection is 3 times greater than people with levels above 40 ng/ml.
• What to do: Get your Vitamin D level checked (either see your doctor, or use an online company such as Everlywell or LetsGetChecked) and orally supplement if your levels are low. It can take a while for Vitamin D levels to rise, so you’re best protected after several months of supplementation. When shopping for a supplement, be sure to look for a Vitamin D supplement with D3 (instead of D2).

Probiotics (in foods and supplements)

• What the science says: The data were VERY mixed here, with a blend of good studies and some not-so-good studies. But overall, in both children and adults, use of probiotics reduced incidence of colds by 30-50%, cut duration of symptoms in half, and even halved school absences, with minimal side effects. The precise mechanism isn’t fully clear, but it is clear that the GI tract plays a significant role in total body immunity and inflammation.
• What to do:
  • Minimize: Processed foods, artificial sweeteners, sugar sweetened beverages
  • Eat: whole nutrition (as recommended in the nutrition section above), plus yogurt with live cultures (Chobani, Fage, and Siggi’s are a few of our favorites). Buy the yogurt plain, then add fruit or just a hint of honey, to keep sugar intake low. Other foods rich in probiotics include sauerkraut (we’re obsessed with Wildbrine Organic Sauerkraut, which you can find at Whole Foods, Costco, and Walmart), miso, pickles, kombucha, and a host of other probiotic-rich foods. Additionally, try to eat foods rich in fiber, which provides the “probiotics” to feed the microbiome bugs ☺.
  • Supplements: Here are a few that we like: Evivo for babies (full disclosure: Darria has worked with them in the past; she doesn’t anymore, just likes the science and gave this product to her youngest), andKlaire Labs Probiotic is recommended by our TrueveLab friend and practicing pediatrician, Dr. Tanya Altman. Ask your own doctor or see below for a few other options. Microbiome Labs MegaSporeBiotic, the following were given a score of 90/100 or above on Labdoor Probiotic Quality rating: Culturelle Digestive Health Probiotic, Ortho Molecular Products Ortho Biotic, or Florastor Daily Probiotic Supplement.

Vitamin C

• What the science says: Studies in labs and in humans show that Vitamin C plays a key role in regulating our immune response, particularly a class of cells called T-cells. It also protects our cells from oxidative injury. In studies of Vitamin C and its effect on colds, people who took Vitamin C over a 60-day winter period had half the number of “cold” days, and approximately half the duration of symptoms of those who did not take Vitamin C. Of note, Vitamin C’s effects seem greatest if taken preventively – not only when symptoms
• What to do: First of all, include foods rich in Vitamin C in your diet. But studies find benefit at levels from consuming around 2 grams per day – which would be around 20 oranges (that’s a lot of peeling). So, during the winter, it’s not unreasonable to up your intake by 500-1000mg / day. However, keep in mind: high doses of Vitamin C can precipitate kidney stones in some people and interact with some medications. And, like anything – you can have too much of a good thing – avoid taking higher doses, unless under the guidance of your physician.

Honey (for littles older than a year)

• What the science says: When the American Academy of Pediatrics recommended AGAINST giving cough and cold medications to children under 4, many parents wondered what to DO. In one randomized trial of almost 300 children, those who received honey before bed experienced approximately 80% less nocturnal cough, severity, and irritation, without any additional side effects. In another review, honey was actually more effective than diphenhydramine (Benadryl).
• What to do: Give children above 1 year old ½ to 1 teaspoon of honey – either straight or diluted in liquid (like warm water or juice).

Zinc

• What the science says: Zinc has anti-viral properties and can halve the duration of and reduce the severity of a cold if taken within 24 hours of symptoms
• What to do: Take orally (we recommend avoiding the nasal route, due to risk of side effects), 50mg 1-2 times a day when symptoms start. Take with food, or your stomach will NOT thank you.

Elderberry

• What the science says: in two separate studies (total of over 1,000 volunteers), elderberry given within 48 hours of symptom onset cut cold symptoms in half (3-4 days, vs. 7-8 days), and reduced severity of symptoms. One study also noted that elderberry users took significantly fewer painkillers and used less nasal spray. One additional double-blinded randomized controlled study (meaning a good quality design of a study) gave elderberry preventatively to airplane passengers for 10 days prior to travel (assuming a high risk of exposure to germs while traveling). In those who received elderberry, while there was no significant difference in the number of cold episodes, the duration of symptoms dropped from 7 to 5 days, with severity reduced by about 10% in the elderberry group. While those aren’t huge gains, they’re valid.
• What to do: Opt for elderberry within 48 hours of symptom onset, and take for 3-5 days. In some situations (such as overseas travel), you may wish to take it preventively, but otherwise, it’s typically used after symptoms start.