Table 2.
Biochemical outcomes for treatment studies of cobalamin injections for autism spectrum disorder. Clinical global impression scale (CGI); subcutaneous (SC); years old (yo).
| Study | Participants | Treatment | Outcomes |
|---|---|---|---|
| Subcutaneous Methylcobalamin Injections | |||
| Bertoglio et al., 2010 [55] DBPC Crossover |
30 | 64.5 µg/kg SC every 3 days | Significant improvements in GSH and the GSH redox ratio in a subgroup of 9 children who were considered “responders” |
| Hendren et al., 2016 [35] DBPC Parallel |
57 | 75 µg/kg SC every 3 days | Clinical improvements were positively associated with increased plasma methionine, decreased SAH, and improved methylation compacity as measured by the SAM/SAH ratio |
| James et al., 2004 [8] Prospective Uncontrolled |
8 | 75 µg/kg 2x/wk for 1 month with folinic acid and betaine | Decreased adenosine and GSSG; increased methionine, cysteine, tGSH, SAM/SAH, and tGSH/GSSG |
| James et al., 2009 [11] Prospective Uncontrolled |
40 | 75 µg/kg 2x/wk for 3 months with folinic acid | Increased cysteine, cysteinylglycine, and GSH;decreased GSSG |
| Frye et al., 2013 [53] Prospective Uncontrolled |
Clinical improvements associated with biochemical improvements in GSH redox status | ||
| Geier and Geier 2010 [56] Retrospective, controlled | 24 | 75 µg/kg SC every 1–3 days | Urinary and plasma cobalt levels higher in mB12 group |
| Intramuscular Methylcobalamin Injections | |||
| Nashabat et al., 2017 [51] Retrospective Uncontrolled |
cB12 switched to mB12; one child received hB12 | Improvement in anemia and metabolic acidosis when cB12 was changed to mB12; homocysteine normalized with 10 mg of hB12 orally in one child | |
| Oral Cobalamin with Other Vitamins | |||
| Adams et al., 2011 [49] DBPC Parallel |
141 | 500mcg Daily Orally | Improvements in total sulfate, SAM, reduced GSH, GSSG:GSH, nitrotyrosine, ATP, NADH, and NADPH |
| Kaluzna-Czaolinska et al., 2011, [44] Prospective Uncontrolled |
30 | B12 1200 mcg per day with vitamin B6 200 mg and folic acid 400 µg | Reduction in urinary homocysteine |
| Cobalamin with Route of Administration Not Specified | |||
| Delhey et al., 2017 [45] Prospective Uncontrolled |
127 | Any B12 taken in 38% of Patients along with other supplements | Improved coupling of Complex I and Citrate Synthase mitochondrial enzymes |
| Nakano et al., 2005 [52] Prospective Uncontrolled |
13 | mB12 25–30 µg/kg/day (up to 1500 µg) for 6–25 months | Increased B12 blood concentrations |