On 2013 Oct 28, John Cannell commented:

The control group in this study was flawed. The authors used children undergoing outpatient tonsillectomies as controls. Such children are likely to have low 25(OH)D levels.

Seventy-eight percent of Auckland children undergoing tonsillectomy had vitamin D insufficiency.

Reid D, Morton R, Salkeld L, Bartley J.Vitamin D and tonsil disease--preliminary observations. Int J Pediatr Otorhinolaryngol. 2011 Feb;75(2):261-4.

Also, 25(OH)D levels of children with ear infections were about one-half that of community controls.

Cayir A, Turan MI, Ozkan O, Cayir Y, Kaya A, Davutoglu S, Ozkan B.Serum vitamin D levels in children with recurrent otitis media. Eur Arch Otorhinolaryngol. 2013 Mar 30.

In addition, in a prospective study, lower serum 25(OH)D levels were associated with increased risk of laboratory-confirmed respiratory tract infections RTI in children.

Science M, Maguire JL, Russell ML, Smieja M, Walter SD, Loeb M. Low serum 25-hydroxyvitamin D level and risk of upper respiratory tract infection in children and adolescents. Clin Infect Dis. 2013 Aug;57(3):392-7.

As Molloy et al did not use community controls, they did not find lower 25(OH)D levels in children with ASD compared to controls but 3 studies of ASD and 25(OH)D using community controls have found significant differences.

Gong ZL, Luo CM, Wang L, Shen L, Wei F, Tong RJ, Liu Y.Serum 25-hydroxyvitamin D levels in Chinese children with autism spectrum disorders. Neuroreport. 2013 Oct 1.

Meguid NA, Hashish AF, Anwar M, Sidhom G.Reduced serum levels of 25-hydroxy and 1,25-dihydroxy vitamin D in Egyptian children with autism. J Altern Complement Med. 2010 Jun;16(6):641-5.

Mostafa GA, Al-Ayadhi LY.Reduced serum concentrations of 25-hydroxy vitamin D in children with autism: relation to autoimmunity. J Neuroinflammation. 2012 Aug 17;9:201.

On 2013 Oct 28, John Cannell commented:

The control group in this study was flawed. The authors used children undergoing outpatient tonsillectomies as controls. Such children are likely to have low 25(OH)D levels.

Seventy-eight percent of Auckland children undergoing tonsillectomy had vitamin D insufficiency.

Reid D, Morton R, Salkeld L, Bartley J.Vitamin D and tonsil disease--preliminary observations. Int J Pediatr Otorhinolaryngol. 2011 Feb;75(2):261-4.

Also, 25(OH)D levels of children with ear infections were about one-half that of community controls.

Cayir A, Turan MI, Ozkan O, Cayir Y, Kaya A, Davutoglu S, Ozkan B.Serum vitamin D levels in children with recurrent otitis media. Eur Arch Otorhinolaryngol. 2013 Mar 30.

In addition, in a prospective study, lower serum 25(OH)D levels were associated with increased risk of laboratory-confirmed respiratory tract infections RTI in children.

Science M, Maguire JL, Russell ML, Smieja M, Walter SD, Loeb M. Low serum 25-hydroxyvitamin D level and risk of upper respiratory tract infection in children and adolescents. Clin Infect Dis. 2013 Aug;57(3):392-7.

As Molloy et al did not use community controls, they did not find lower 25(OH)D levels in children with ASD compared to controls but 3 studies of ASD and 25(OH)D using community controls have found significant differences.

Gong ZL, Luo CM, Wang L, Shen L, Wei F, Tong RJ, Liu Y.Serum 25-hydroxyvitamin D levels in Chinese children with autism spectrum disorders. Neuroreport. 2013 Oct 1.

Meguid NA, Hashish AF, Anwar M, Sidhom G.Reduced serum levels of 25-hydroxy and 1,25-dihydroxy vitamin D in Egyptian children with autism. J Altern Complement Med. 2010 Jun;16(6):641-5.

Mostafa GA, Al-Ayadhi LY.Reduced serum concentrations of 25-hydroxy vitamin D in children with autism: relation to autoimmunity. J Neuroinflammation. 2012 Aug 17;9:201.