Effect of vitamin supplementation on micronutrient concentrations in blood and intracellular tissue
The first patient was enrolled in October 2008 and the last patient finished the study in March 2009. After excluding subjects with prior additional vitamin supplement use, we included those with a measured value before and after supplementation for analysis. Table summarizes micronutrient levels in blood before and after supplementation. Most nutrients were well within the reference ranges or above, suggesting no overt malnutrition. However, before supplementation, seven participants had α- and β-carotene concentrations below the reference values. For zinc levels, 1 of 12 women had a concentration below the reference, whereas 14 (77.8%) men had a zinc concentration below the reference value. No significant change in zinc, retinol, or vitamin C was found after 2 months. A significant increase in plasma concentration after supplementation was, however, detected for α-carotene; β-carotene; vitamin E; lutein; vitamins B1, B6, and B12; and folic acid. After supplementation, all α-carotene levels were in the normal range. Only three persons had β-carotene levels below the reference value after supplementation. Lower levels of lycopene concentration were seen after supplementation, with the number of participants having lycopene levels under the reference value doubling afterward.
Micronutrient levels in serum/plasma before and after supplementation are shown
Table shows the micronutrient concentrations in BMC before (n = 42) and after (n = 37) supplementation. Samples with concentrations below the detection level (n = 11) and with missing values (n = 24) before supplementation were excluded. Therefore, only seven patients were included for vitamin C analysis. We did not find significant changes in micronutrient concentrations in BMC. Of note, however, is that the number of patients with concentrations of vitamin C above the detection limit increased. Before supplementation, 11 (26.2%) subjects had a vitamin C concentration below the detection level, whereas afterward all measured vitamin C levels (n = 28) were above the detection level. To assess the intracellular vitamin supply in B vitamin metabolism, we analyzed specific metabolites; for vitamin B12, TC and MMA were used. Hcy increases in intracellular vitamin B6, vitamin B12, and folic acid deficiency. Low ETKA and a high TPP effect are markers for thiamine deficiency. TC, which carries the biologically available vitamin B12, increased significantly (P < 0.01) after supplementation (Table ). Only two subjects had an MMA concentration > 47 μg/L, indicating vitamin B12 deficiency prior to supplementation. No significant decrease in MMA levels after supplementation was detected. After supplementation, Hcy levels decreased significantly (P < 0.001). Before supplementation, plasma levels of Hcy were elevated in 15 subjects, whereas afterward only five subjects had elevated Hcy concentrations. Although there was no significant change in ETKA, the decrease in the TPP effect was highly significant after supplementation.
Micronutrients in cells of buccal mucosa before (B) and after (A) supplementation are shown
MMA, Holo-TC, Hcy, Transketolase, and the TPP-effect in serum/plasma before and after supplementation
Effect of vitamin supplementation on nutritional and health status
Nutritional data are shown in Table . None of the volunteers was undernourished. Before supplementation, 25 (61%) subjects were well nourished, and 23 (63.9%) were afterward. Sixteen (39%) subjects were at risk for malnutrition before supplementation and 13 (36.1%) afterward. The risk for malnutrition was mainly attributable to a poor subjective assessment of health status, selection of food, or multi-medication. Comparison of the MNA scores of all 36 volunteers revealed no significant change (B: 24.27 ± 2.38; A: 24.64 ± 2.28). However, when the MNA scores of the well-nourished subjects and those at risk for malnutrition were analyzed separately, the score of the subjects at risk for malnutrition increased significantly after supplementation (B: 21.93 ± 1.45; A: 22.75 ± 1.25; P < 0.05), whereas the scores of the well-nourished subjects showed no difference (B: 25.76 ± 1.46; A: 25.84 ± 1.95). The MMSE scores were unchanged subsequent to supplementation.
Nutritional status before and after supplementation
To analyze changes in health status by supplementation, the MNA asks how test persons consider their health status in comparison with others of the same age. After supplementation, none of the participants reported their health status as “not as good,” whereas prior to supplementation, four (11.1%) did so. Furthermore, those who considered their health status as “better” increased by 16.6% and those who considered it to be “as good” decreased by approximately 8.3%. The improvement of the subjectively assessed health status was also the main reason why the subjects achieved better MNA scores after supplementation.