Changes in vitamin status in plasma during dieting and exercise.

The micronutrient status of 12 obese male subjects was evaluated before and after a 14-week period of a low energy diet (3.0-3.9 MJ) with or without an exercise (5 h p/w) treatment. The subjects were matched on the basis of their body mass index (BMI kg/m2) into a diet group (D; average BMI 32.2) and a diet-exercise group (DE; average BMI 32.9). After 14 weeks both groups showed similar results in term of weight loss (D 15.1; DE 16.4 kg), fat loss (D 11.7; DE 13.6 kg) and loss of fat free mass (FFM) (D 3.4; DE 2.8 kg). With respect to changes of the micronutrients in blood plasma only the decrease in ferritin was significantly different between D and DE (P less than 0.05), with a larger decrease for DE. In both groups significant decreases of about 20% in fat soluble vitamins were observed. Water soluble vitamins demonstrated a large variation between individuals and decreases were not significant.