To evaluate the difference between vitamin C in the form of oral liposomes and general vitamin C in a fixed period of time in plasma and urine.

we recruited 11 healthy subjects and adopted a cross-over test. the subjects need to take 3 tests during trail. After each test was completed, a washout period of 14 days was required before the next test start. The subjects were informed to consume one sachet vitamin C without liposome, liposomal process A vitamin C, or liposomal process B vitamin C (Double Nutri™) every test, and vitamin C concentration was measured at baseline (0 hours), 0.5, 1, 2, 3, 4, and 8 hours after taking test sample.

Inclusion Criteria:

1. Adults between 20-60 years old,
2. No heart, liver, kidney, endocrine and major organic diseases

Exclusion Criteria:

1. Renal insufficiency and dialysis
2. Cancer
3. Underweight (BMI≦17) or obese (BMI≧27),
4. Take chronic disease drugs,
5. Blood pressure systolic blood pressure ≧130 mmHg or diastolic blood pressure ≧85 mmHg,
6. Too high fasting blood glucose ≧ 100 mg/dL,
7. Triglyceride ≧ 150 mg/dL,Total cholesterol ≧ 200 mg/dL,
8. Have a history of vitamin C allergy,
9. People with mental illness,
10. Pregnant or breastfeeding women,
11. Hematosis,
12. Kidney stones,
13. Long-term vitamin C supplements (at least 200 mg per day for more than one month)