The HPLC methods are intended for the quantitative determination of Vitamin A/E, C, B6 and K1 in plasma and serum, and Vitamin B1 in EDTA-blood.

Vitamin A (Retinol) and Vitamin E (Tocopherol) are fatsoluble vitamins, which could be stored for longer periods in the adipose tissue. Both, lack and excess could express in complaints.

Vitamin B1 (thiamin) plays an important role in carbohydrate- and animo acid metabolism.

Vitamin B6 functions as a coenzyme and is essential in the protein metabolism, thereby synthesizing, transforming or degrading animo acids.

Ascorbic acid (Vitamin C) plays an important role in hydroxylation reactions, i.e. in the synthesis of collagen.

Decreased Vitamin K1 levels can be found in osteoporotic patients and patients with clotting disorders.