The Effect of Fish Oil, Vitamin D and Protein on URTI Incidence in Young Active People

Abstract

Upper respiratory tract infection (URTI) is a frequent illness among athletes. We investigated the effect of a multi-nutrient supplement (vitamin D, fish oil and protein) on the occurrence of URTI in young active people. Forty-two young recreational athletes were randomly assigned to receive either a supplementation (550 mg DHA, 550 mg EPA, 10 µg vitamin D3 and 8 g whey protein) or placebo for 16 weeks. Unstimulated saliva samples were collected by passive drool. Samples were analysed for IgA (sIgA) concentration and the secretion rate extrapolated by multiplying concentration by saliva flow rate. Physical activity levels and URTI incidence were monitored by questionnaire. Training status was not different between the 2 groups. There were no differences in the incidence, severity and duration of URTI. However the number of symptom days was lower in the supplemented compared to the control group (1.72 ± 1.67 vs 2.79 ± 1.76; P < 0.05). sIgA concentration and secretion rate did not differ between groups. This study demonstrates that 16 weeks of supplementation with fish oil, vitamin D and protein did not modify the incidence, severity and duration of URTI, although the total number of symptom days was reduced, in a healthy active population.

Vitamin D, Immune function and acute respiratory infection among athletes; A Systematic Review

“…One observational study [15] showed significantly greater symptom severity scores among vitamin D deficient athletes. In contrast, two RCTs [12,14] (1 of which was conducted among vitamin D insufficient subjects) consistently showed no difference in reported symptom severity scores between supplemented and unsupplemented groups. One RCT 9 among vitamin D insufficient athletes showed that vitamin D supplemented subjects had significantly lesser total symptoms per ARI episode compared to the placebo group.…”

“…All randomized controlled studies administered oral vitamin D3 to participants in the intervention arm given as a daily dose. One of the studies [14] did not have vitamin D as the sole supplement; it included fish oil and protein. Table 1 presents the characteristics of eligible studies (2018) [16] 53 All female --------N/A High vitamin D concentrations seen in subjects Fikratkerimov et al…”

“…One observational study [15] showed significantly longer duration of symptom days among vitamin D deficient athletes compared to those with optimum/adequate/inadequate vitamin D status. Out of 2 RCTs, one study [14] showed significantly shorter duration of symptom days in the vitamin D supplemented group compared to a placebo group, but information regarding baseline serum vitamin D levels could not be obtained. One observational study [15] showed significantly greater symptom severity scores among vitamin D deficient athletes.…”

“…Immune function markers examined were the following: salivary IgA, cathelicidin, TNF-α. A few studies consistently showed that vitamin D supplementation increased salivary IgA secretion rate [14,15] and cathelicidin concentration and secretion rates [10,15] . Vitamin D (as serum concentration or use as a supplement) did not appear to influence other markers of immune function.…”

Nutraceuticals and herbal extracts: A ray of hope for COVID‑19 and related infections (Review)

“…Linday et al (98) found that the simultaneous administration of cod liver oil (which contains EPA and vitamin A) and a multivitamin-mineral supplement to children led to a statistically significant (P<0.05) decrease in the mean number of URTI-related medical consultations over time. Overall, omega-3 fatty acids confer significant health benefits to patients with URTI complications and shorten the length of stay of acutely ill patients in hospital (99)(100)(101). Since omega-3 fatty acids have proven to be effective in reducing airway inflammation and bronchoconstriction, have also exhibited efficacy against viral infections (102,103), their potential for use against COVID-19 warrants further investigation (104)(105)(106).…”