Whey protein isolate (WPI) contains vitamin B12 and folate. However, the efficacy of WPI as a bioavailable source of these vitamins in the elderly with low vitamin B12 was not previously tested. We investigated the effects of WPI supplementation on vitamin B12 and folate status in blood and measured changes in homocysteine (HCY), methylmalonic acid (MMA), and genome integrity biomarkers in elderly individuals with low vitamin B12 status. The effect of WPI was compared to soy protein isolate (SPI).Methods and results:
In this randomized controlled cross-over intervention trial, 56 subclinically vitamin B12-deficient participants received 50 g WPI or 50 g SPI as a control for 8 wk followed by 16-wk washout phase and then cross-over to alternative supplement for next 8 wk. Consumption of WPI resulted in significant increase in serum active B12 (p < 0.0001) and serum folate (p = 0.0094). MMA, HCY, and nucleoplasmic bridges increased significantly after SPI intake but not after WPI (p = 0.052; p = 0.028; p = 0.0009, respectively).Conclusion:
Results indicate that WPI consumption improves active B12 and folate status. Unlike SPI, WPI consumption may prevent increase in MMA, HCY, and genome instability in older Australians with low vitamin B12 status.