Lowered immunity or own goal?

Under the headline “Lowered immunity”, a well-known nationwide German daily newspaper covers the topic of common cold and vitamin D. “Vitamin D does not prevent you from common colds – different from what we thought” is the title of the chief editor, is famous for his vitamin-criticism. The fact that inclined (or, no more inclined, as far as I am concerned) readers get a completely different picture of the data because crucial information is omitted, shows how biased the reports about vitamins are today.

It is about the study „Effect of High-Dose vs Standard-Dose Wintertime Vitamin D Supplementation on Viral Upper Respiratory Tract Infections in Young Healthy Children“ which was conducted by a Canadian group of researchers around Mary Aglipay and Jonathan Maguire. For their study, 700 children aged 1 to 5 took a daily supplement of either 400 IU or 2000 IU vitamin D. The occurrence of respiratory diseases during this period was documented. The result showed no significant differences between the two groups concerning the occurrence of common colds and influenza.

These data support the opinion of the author of the article “Lowered immunity” that vitamin D is among the substances for which the credo must be “hope is stronger than effect”. He even writes about “the destruction of yet another myth around vitamin D”.

What he conceals in his article: The children participating in this study had average vitamin D levels of 90 or 92 nmol/l (35,9 or 36,9 ng/ml), which means that they already had ideal vitamin D levels when this study started. In Canada, like here, plasma levels of over 75 nmol/l are considered optimal.

Of course, the benefit of a supplementation decreases when the levels in the plasma of a given vitamin increase. Furthermore, it is in the definition of an ideal status that an increase in levels does not provide humans with health benefits. And this is exactly what this study shows. Little children aged 1 to 5 do not need high doses if they already have very good levels. 400 IU/day is sufficient. The lack of a control group without vitamin D supplementation is due to the methodology of the study but would have been quite insightful. Indicating this lack would have not harmed a quality article either.

What we should not forget here: Austrian pupils (and their pediatrics) can only dream of such good levels of vitamin D: 62,3% of girls and 55,8% of boys suffer from slightly (25 – 50 nmol/l) or significantly ( < 25 nmol/l) lowered vitamin D levels (as we can see in the Austrian Study of Nutritional Status). In Germany, the situation is quite similar, with 63% of boys and 64% of girls with lowered vitamin D levels below the critical value of 50 nmol/l (according to a KIGGS study with more than 10.000 children). It has been proven scientifically that vitamin D is necessary for the immune system of children. The Canadian Pediatric Society for example determined: that with evidence Level III it has been proven that vitamin D plays an essential role in the regulation of cell growth, the immune system, and cell metabolism. Moreover, pediatricians think that it can be necessary to supplement up to 2,5 µg/kg/d to reach an optimal level of > 75 nmol/l.

My conclusion: high-quality journalism informs its readers about a topic in a balanced way. However, the issues of vitamins, minerals, and supplementation are barely treated with this journalistic credo – journalists keep repeating the same biased articles, which irritates the readers.

Do not get me wrong: we have to be able to express personal opinions freely – no matter whether pro or con supplements. But they should be marked, as commentary, opinion, or blog. In ignoring this boundary, journalists abuse their positions as independent sources of information. This is harmful for everybody and ultimately leads to an own goal: according to a survey of the EU Commission, only half of EU citizens consider the press as credible.

I belong to the other half.

 Sources:

Werner Bartens: „Abwehrschwächen“. Titelseite der Süddeutsche Zeitung vom 19. Juli 2017

Aglipay M et al: “Effect of High-Dose vs Standard-Dose Wintertime Vitamin D Supplementation on Viral Upper Respiratory Tract Infections in Young Healthy Children”. JAMA. 2017 Jul 18;318(3):245-254.

Canadian Pediatric Society, Godel et al. “Vitamin D supplementation: Recommendation for Canadian mothers and infants”. Paediatr Child Health 2007; 12(7): 583-9.

Europäische Kommission: Spezial Eurobarometer 452. November 2016.