There is an interest to assess nutritional status of vitamins in humans in a non-invasive way, i.e. by avoiding taking blood samples. Saliva could potentially be an alternative to blood for this purpose. The suitability of saliva for status determination will be investigated by analysis of (forms of) vitamins A and E, B1, B2, B3, B6 and C in both saliva and blood.

There is an interest to assess nutritional status of vitamins in humans in a non-invasive way, i.e. by avoiding taking blood samples. Saliva could potentially be an alternative to blood for this purpose. However, literature data on vitamins in saliva is scarce. The occurrence is best demonstrated for 25-hydroxy-vitamin D3 where already indications for a correlation to blood levels have been observed in a small scale supplementation study. Occurrence of (forms of) vitamins A and E, B1, B2, B3, B6 and C has been reported but is less well documented. Some information is somewhat ambiguous and for none of these latter vitamins blood levels have been investigated in parallel to saliva.

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

A total of 50 subjects (females and males, with at least 40% of each gender) generally regarded as healthy in the age of 20 - 65 years.