Critique of the VIDARIS randomized controlled trial on vitamin D and URTIs

¶ … Vitamin D in Controlling URTIs

In recent times, several experimental studies have been conducted in order to understand the impact of vitamin D on controlling Upper Respiratory Tract Infections. This paper has selected by article "Effect of vitamin D3 supplementation on upper respiratory tract infections in healthy adults: the VIDARIS randomized controlled trial," a research study conducted by Murdoch et.al (2012). The goal of the article critique is to thoroughly analyze the article and to determine its validity and reliability. Furthermore, the critique would help in understanding the impact of Vitamin D on URTIs in healthy adults.

Experimental studies have reported that the relationship between serum 25-hydroxyvitamin D (25-OHD) and upper respiratory infections is inversely proportional. Murdoch et.al (2012) has reported that results of these experimental studies have been found to be inconclusive. The goal of Murdoch et.al (2012) was to study the impact of vitamin D on Upper respiratory infections (URTIs). The experiment lasted for a period of ten months and was conducted in Christchurch in New Zealand. A sample of 322 healthy adults was collected through random sampling. Dosage quantity had been divided in the following manner; 200000 IU oral vitamin D3 at the initial stage, 200,000 IU for a period of one month the following month and lastly, 100,000 IU later onwards. From the results, it was revealed that the dosage of 100, 000 IU of vitamin D did not have the ability to reduce the severity of URTIs in adults, who were healthy.

Critique

Participants of the study were screened and enrolled through an advertisement campaign. Participants were selected in accordance to criteria of enrollment as the advertisement campaign had been used to screen the individuals, the researchers were looking for. Exclusion criteria had been established in order to ensure that the trial's outcome is not influenced in any way and since the participants were screened thoroughly, therefore, it is safe to conclude that it did not influence the conclusion of the experiment.

After establishing the eligibility condition, computer generated randomization had been conducted to give participants vitamin D or placebo randomly. Both tablets appeared to be identical. Table 1of the research, demonstrated that the baseline characteristics of all the groups were balanced evenly on basis of the characteristics established. Both groups contained equal number of participants and therefore, did not influence the results and outcomes of the study.

The authors stated that the 91% of the participants took complete part in the treatment as well as in the follow up study. However, the measures for determining this result had not been stated by the authors and in this type of research, participants were not allowed to take any type of medications that would influence their results. About 6% of the participants completely withdrew from the research and the 3% did not take part in the treatment but were active in 18 months follow up program.

The findings of the research conducted by Murdoch et.al (2012) also gave the same results: 100000 IU of Vitamin D3 was not effective enough to control URTIs in healthy adults. The researchers also concentrated on changing their dosage and came to the conclusion that "result remained unchanged when the analysis included winter season or baseline 25-OHD levels" (Murdoch et.al, 2012). The findings of the experimental study are conclusive with literature. Similar experimental studies have been conducted by Laaksi et.al among 164 soldiers, for a dosage of 400 IU of Vitamin D3 (Murdoch et.al, 2012).

Limitations

The limitation of the study was that the researchers did not evaluate the impact of Vitamin D in terms of preventing the disease, which occurred because of individual viruses. Data regarding this is insufficient and therefore, also requires future research (Murdoch et.al, 2012). Therefore, external validity of the research may be questioned.

Conclusion

Experimental studies have been conducted in order to understand the impact of vitamin D on controlling Upper Respiratory Tract Infections. The goal of Murdoch et.al (2012) was to study the impact of vitamin D on Upper respiratory infections (URTIs). The results from the experimental studies conducted to understand the impact of vitamin D dosage on VRTIs have given results, which conflict with one another and the findings of the research conducted by Murdoch et.al (2012) also gave the same results: 100000 IU of Vitamin D3 was not effective enough to control URTIs in healthy adults.