An individual’s unique nutritional requirements can be assessed with laboratory testing. Analysis of blood samples can pick up most vitamin deficiencies. There are several different tests that can be performed on blood to determine vitamin status and some are much more meaningful and accurate than others are. I recommend performing functional tests as much as this is possible. Specifically, the activity of enzymes requiring the activation of a particular vitamin can be measured. For example, an enzyme called transketolase can be isolated from red blood cells. Transketolase requires vitamin B1 as its coenzyme in order to function. This enzyme can be measured as a test of vitamin B1 status. The laboratory measures the activity of the isolated transketolase enzyme. If it is low, vitamin B1 insufficiency is present. Additionally, a second test is performed which picks up more subtle insufficiencies. Vitamin B1 is added to the transketolase enzyme and the activity of this enzyme is measured again. A large increase in transketolase activity after addition of vitamin B1 shows that the enzyme’s activity had been limited by a functional lack of the vitamin. Adequacy of levels of several vitamins can be evaluated by measuring activities of different enzymes. Other vitamins are assessed simply by measuring their concentration within blood or blood cells.
Whereas vitamins are best evaluated from blood samples, most minerals are best measured from hair specimens. The body deposits minerals in the hair, nails, teeth and other tissues. For obvious reasons, hair is the preferred tissue to use. Although pubic hair can be used, scalp hair gives more accurate results. A hair specimen shows the levels of minerals in the body over the past two months. Hair analysis is accurate for evaluating most minerals. I have yet to see an individual not lacking in at least one mineral on hair analysis.
Sample Fat-Soluable Vitamins Test Report