Table 2.
Studies that considered blood ascorbid acid (AA) levels.
| First Author, Year [Reference] |
Study Design | Setting | Number of Subjects (M-F) Mean Age |
Primary Outcomes | Micronutrient Serum Concentration Osteoporosis | Micronutrient Serum Concentration Osteopenia | Micronutrient Serum Concentration Normal | Micronutrient Serum Reference Value | % Subjects < Reference Value | Results |
|---|---|---|---|---|---|---|---|---|---|---|
| Maggio D., 2003 [21] | Cross-sectional, case-control study | Free-living subjects | 150 F 75 osteoporosis (70.4 ± 8.5 y) 75 controls (68.8 ± 3.5 y) |
Plasma AA, vitamin E, and A; uric acid; superoxide dismutase, glutathione peroxidase | Plasma AA: 30 ± 3.7 μmoL/L | // | Plasma AA: 55.5 ± 13.1 μmoL/L | // | None of the subjects belonging to the two groups had levels below the normal AA range. | Dietary and endogenous antioxidants consistently lower in osteoporotic than in control subjects |
| Falch J.A., 1998 [22] | Case-control study | Cases admitted to the hospital and home-living controls | 40 81 ± 5 y (20 cases with a recent hip fracture + 20 controls) |
Serum AA concentration | Patients with a recent hip fracture: 34 ± 19 μmoL/L | // | Controls: 54 ± 30 μmoL/L | // | // | Serum AA concentration significantly lower in the hip fracture patients. |
| Martínez-Ramírez M.J., 2007 [23] | Hospital-based case-control study | Hospital of Jaén, Spain | 334 (167 cases + 167 controls) (80% F) | Osteoporotic fractures | In cases: 19.31 μmoL/L | // | In controls: 23.28 μmoL/L | // | // | Statistically significant difference between cases and controls for AA blood levels. Association between serum AA and fracture risk, with a significantly reduced risk for the upper quartile. |
| Lumbers M., 2001 [24] | Case-control study | Cases: hospital patients admitted for emergency surgery for fractured neck of femur. Controls: independent-living females | 125 F 75 cases (80.5 y) 50 controls (79.8 y) |
Levels of plasma albumin, transferrin, C-reactive protein (CRP), cholesterol, AA, Se, Zn, total antioxidant status, Se-dependent glutathione peroxidase activity. | Hip fracture patients Plasma AA: 42.7 ± 21.4 μmoL/L |
// | Controls Plasma AA: 20.8 ± 14.2 μmoL/L |
// | // | Fracture patients: higher plasma AA levels. |