Occurrence of Selected Vitamins in Saliva and Blood

Inclusion Criteria: * Generally healthy males and females * Age: 20-65 years * Non-smokers * No recent or recently (within the last four weeks) started intake of vitamin supplements; long-term intake of supplements on regular base is o.k., but needs to be documented (type of supplement and dosage) * Subjects willing and able to give written informed consent and to understand, to participate and to comply with the biomedical research project requirements. Exclusion Criteria: * Any condition that, in the investigator's opinion would impact volunteer safety and/or a volunteer's ability to complete all study related procedures. (e.g. psychiatric illness, drug addiction, alcoholism, etc.) * Known infection with human immunodeficiency virus (HIV) or hepatitis. * Chronic intake of substances affecting blood coagulation (e.g. acetylic acid, anticoagulants, diuretics, thiazides), which in the investigator's opinion would impact volunteer safety * Allergy or known hypersensitivity against disinfection solutions * Women: pregnancy, or during lactation * Currently participating in another study