| The purpose of this study was to determine serum levels of cholesterol and vitamin A (retinol), carotenoids (total carotenoids, beta-carotene, and lycopene), and vitamin E (alpha-tocopherol) in four populations at varying risks for cancer. The relationships between serum vitamin A, carotenoids, vitamin E, and cholesterol was evaluated within each of these populations.;As the high-risk cancer populations, the spinal cord injured patients (SCI, N = 54) and alcoholics (ALC, N = 69) were studied. As the low-risk canacer populations, healthy American young males (HEA, N = 38) and African medical students (AFR, N = 48) were studied.;The level of serum total cholesterol was significantly correlated with the level of serum retinol in the SCI (r = .23: p < .05), ALC (r = .38: p < .001), and AFR (r = .31: p < .05). Serum total cholesterol level was correlated with serum total carotenoid level in the SCI (r = .33: p < .01), AFR (r = .57: p < .001), and HEA (r = .44: p < .001). Serum total cholesterol level was highly correlated with serum beta-carotene level in the AFR (r = .55: p < .001) and serum lycopene level in the AFR (r = .60: p < .001). Serum total cholesterol level was highly correlated with serum alpha-tocopherol level in the SCI (r = .53: p < .001), ALC (r = .48: p < .001), AFR (r = .38: p < .001) and HEA (r = .30: p < .05). The relationship between vitamin A, carotenoids, vitamin E, and HDL cholesterol and HDL subfractions were studied also and showed variations.;High cancer risk groups had lower beta-carotene and total carotenoids levels than low cancer risk groups, and lower total cholesterol levels than the HEA. The AFR, which had the lowest total cholesterol had the highest beta-carotene and total carotenoid levels. Serum levels of retinol, lycopene, and alpha-tocopherol were not related to the cancer risk of those populations. |
