Handbook of Vitamin C Research

Shortage of Vitamin C Accelerates Aging 381wild -type counterparts, and this observation was documented before SMP30 was identifiedas a GNL (Figure 2). At that time, no symptoms of scurvy were noted in the SMP30/GNLknockout mice, presumably because the autoclaved mouse chow they ate contained ~55mg/kg of vitamin C. We now know that this amount of vitamin C is too small to maintainnormal levels in tissues; in fact, each mice was taken about 2.5% a day of vitamin C.However, we can say that aging progressed ~four times faster than normal in these knockoutmice, because they received too little vitamin C over a long period of time. Thus, theseresults indicate that a shortage of vitamin C accelerated aging. Until now, there was noscientific evidence for this conclusion despite the conventional wisdom that vitamin C has ananti-aging influence. This, then, is the first report of research that used SMP30/GNLknockout mice to show in a scientific manner that the shortage of vitamin C decreased life.Rough Estimate of Vitamin C Intake that Promotes Human AgingThe recommended amount of vitamin C intake daily for humans is about 100 mg (~5 or 6strawberries) according to the "Japanese dietary reference intake of vitamin C" published bythe Japan Ministry of Health, Labor and Welfare. When one takes only 2.5 mg (2.5% of 100mg) of vitamin C for the long term, aging accelerates according to our experiment resultswith the SMP30/GNL knockout mice. However, this calculation does not apply when vitaminC intake stops briefly, i.e., for several days, because the healthy body stockpiles a supply ofvitamin C. Aging accelerates only in the long term when as little as 2.5 mg a day of vitaminC is taken for a period of about three years; after that interval, a vitamin C deficiency can killone in ten individuals according to our rough estimate (Figure 5). Moreover, half of those sodeprivedcan be calculated to die in about 13 years. However, this theoretical value appliesonly to the experimental results in the SMP30/GNL knockout mice and does not guaranteethe same outcome in humans.Figure 5. Rough estimate of vitamin C intake that promotes aging in humans.