Pike 1995Low.

Methods	Randomised, double‐blind, placebo‐controlled trial with parallel group design (two intervention groups).
Participants	Country: United States of America. Number of participants randomised: 47; 13 men and 34 women at age 61 to 79, mean age 69 years. Inclusion criteria: healthy, noninstitutionalised elderly participants with no known chronic or serious medical illness (eg, cancer, end stage renal disease, chronic liver disease). Exclusion criteria: taking nutritional supplements 3 months before the trial start.
Interventions	Participants were randomly assigned to receive: group 1: micronutrient supplement (Multivitol R) containing vitamin A (retinol acetate) 800 retinol equivalents (RE); vitamin D2 (ergocalciferol) 5.0 µg; vitamin E (alpha‐tocopherol acetate) 45 mg; vitamin B1 (thiamin mononitrate) 2.18 mg; vitamin B2 (riboflavin) 2.6 mg; vitamin B6 (pyridoxin hydrochloride) 3.65 mg; vitamin B12 (cyanocobalamin) 9 µg; nicotinamide 30 mg; folic acid 0.4 mg; vitamin C (ascorbic acid) 90 mg; calcium (calcium hydrogen phosphate 2H2O 695 mg) 162 mg; magnesium (magnesium oxyde 165.78 mg) 100 mg; iron (iron (II) fumarate 82.14 mg) 27 mg; copper (copper (II) oxyde 1.87 mg) 1.5 mg; zinc (zinc oxide 28 mg) 22.5 mg; iodine (potassium iodide 0.294 mg) 0.225 mg); (n = 24); group 2: placebo: (n = 23); one tablet daily for a period of one year.
Outcomes	The primary outcome measure was: immune indices in healthy elderly.
Notes	Compliance was verified by interview with the patient during three‐monthly visits to the centre and through morbidity forms, phone calls, and checking supplement containers when brought back to the centre. Five participants in the placebo group and seven in the supplemented group did not complete the trial. Trial agents were provided by Hermes Arzneimittel GmbH.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Sequence generation was achieved using computer random number generation.
Allocation concealment (selection bias)	Low risk	Allocation was controlled by a central and independent randomisation unit, so that intervention allocations could not have been foreseen in advance of, or during, enrolment.
Blinding (performance bias and detection bias) All outcomes	Low risk	The trial was described as blinded, the parties that were blinded, and the method of blinding was described, so that knowledge of allocation was adequately prevented during the trial.
Incomplete outcome data (attrition bias) All outcomes	Low risk	The numbers and reasons for dropouts and withdrawals in all intervention groups were described.
Selective reporting (reporting bias)	Low risk	Pre‐defined, or clinically relevant and reasonably expected outcomes are reported on.
Other bias	Low risk	The trial appears to be free of other components that could put it at risk of bias.