Table 1.

Cobalamin concentration and the clinical relevance.

Cobalamin concentration (pg/ml)	Clinical relevance of value
0	Control value
200	UK minimum of normal range [21]
500	Asian minimum of normal range [22]
750	Midrange of reference range
1000	UK maximum of normal range [21]
5000	Five times greater than maximum range to test for toxicity of extremes