Staying Healthy Through the Winter

I am home with my sick 2-year old daughter today. I thought I had escaped the GI bug, but apparently I was not that lucky. Despite some great research recently on probiotics and vitamin D for supporting immune health in kids (see below), I have not been very consistent in giving them. What a tough reminder to get back on the bandwagon!

1. The first study was published in Pediatrics in August 2009. The double-blind, placebo-controlled trial studied 326 children aged 3-5 years old. The children were given either a single probiotic treatment (Lactobacillus acidophilus) or a combination treatment (Lactobacillus acidophilus and Bifidobacterium lactis) twice a day for 6 months. Probiotic supplementation showed significant support for:
   
   • symptom duration (shortened by 32% in single probiotic group and 48% in combination group)
   • decreased fever (by 53% and 73%)
   • decreased coughing (by 41 and 62%)
   • decreased runny nose (by 58% in the combination group only)
   • decreased antibiotic use (by 68% and 84%)
   • decreased days absent (by 32% and 28%)


2. Another randomized, double-blind, placebo-controlled trial supplemented 281 children in day care centers with Lactobacillus rhamnosus LGG (Culturelle) at a dose of 10 billion cfu per day. Study results suggest that probiotics reduced the risk of developing an upper respiratory tract infection (URTI) and URTI duration. No significant differences were found for lower respiratory tract infections, GI infections, vomiting, diarrhea, or GI symptom duration.


3. Lastly, an analysis published in 2009 suggests that optimal vitamin D levels may also promote respiratory tract health. Low levels of vitamin D has been proposed for years as a contributor to the seasonal variation of cold and flu susceptibility. Research indicates that it promotes innate immunity. One theory is that microbes activate vitamin D which in turn activate genes involved in immune defense. Antimicrobial activity on epithelial cells and macrophages has also been found to be vitamin D dependent. An earlier randomized controlled study found women deficient in vitamin D were three times more likely to report cold and flu symptoms. In the recently published analysis of NHANES (National Health and Nutrition Examination Survey) data, lower blood levels of vitamin D was associated with increased reports of upper respiratory tract infection:
   • 25(OH)D levels less than 10 ng/mL: 24% of people reported URTI's
   • 25(OH)D levels of 10 to less than 30 ng/mL: 20% of people reported URTI's
   • 25(OH)D levels of more than 30 ng/mL: 17% of people reported URTI's (P<.001)

The take home message:

1. Test your vitamin D levels (and supplement with 2,000-4,000 iu daily)
2. Take a daily probiotic (or lots of fermented foods such as tempeh and kombucha)

Now I am off to put 5 billion CFU probiotic powder into my daughter's milk, and give her a few drops of vitamin D!

1. Leyer GJ, Li S, Mubasher ME, Reifer C, Ouwehand AC. Probiotic effects on cold and influenza-like symptom incidence and duration in children. Pediatrics. 2009 Aug;124(2):e172-9.
2. Hojsak I, Snovak N, Abdović S, et al. Lactobacillus GG in the prevention of gastrointestinal and respiratory tract infections in children who attend day care centers: A randomized, double-blind, placebo-controlled trial. Clin Nutr. 2009 Nov 4.
3. Cannell JJ, Zasloff M, Garland CF, Scragg R, Giovannucci E (2008). On the epidemiology of influenza. Virol J. 2008;5(29)
4. Ginde AA, Mansbach JM, Camargo CA. Association Between Serum 25-Hydroxyvitamin D Level and Upper Respiratory Tract Infection in the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2009;169(4):384-390.