ADVIA Centaur Active-B12 Assay
The most common causes of megaloblastic anemia are deficiency of either cobalamin (vitamin B12) or folate (vitamin B9). Your body needs folate and vitamin B12 to produce enough healthy red blood cells. A diet lacking in these and other key nutrients can cause decreased red blood cell production. Additionally, some people may consume enough vitamin B12, but their bodies aren't able to process the vitamin. This can lead to vitamin deficiency anemia, also known as pernicious anemia.
- A deficiency in vitamin B12 can result in varying degrees of neuropathy or nerve damage. In severe cases, mental changes that range from confusion and irritability to dementia may occur1.
- Pregnant women need increased folate for proper fetal development because of the added stress of rapidly growing fetal cells. A folate deficiency during pregnancy, especially in the early weeks when a woman might not know she is pregnant, may lead to premature birth and neural tube birth defects (NTDs) such as spina bifida in the child1.
Vitamin B12 in serum is bound to two proteins: transcobalamin (TC) and haptocorrin (HC). The transcobalamin vitamin B12 complex is called holotranscobalamin (holoTC). HoloTC is also known as active-B12 as it contains the biologically available cobalamin, as only holoTC promotes the uptake of cobalamin by all cells via specific receptors. HoloTC has been shown to be superior to other relevant lab parameters in B12 deficiency, such as serum total cobalamin and methylmalonic acid (MMA), for diagnosing vitamin B12 deficiency2.
Laboratory testing is used to detect a vitamin deficiency, determine its severity, establish it as the underlying cause of someone's symptoms, and to monitor the effectiveness of treatment.1
What are the signs and symptoms of vitamin B12 deficiency?3,4
Vitamin B12 deficiency associated signs and symptoms could take years to manifest in adults. Infants and children will show signs of deficiency much sooner because they have not yet had time to store sufficient amounts. People with vitamin B12 deficiency may encounter symptoms such as:
- Weakness and light-headedness
- Shortness of breath
- Loss of balance
- Yellowed skin
- Strange sensations, numbness, or tingling in the hands, legs, or feet
Who is likely to develop vitamin B12 deficiency?
- The elderly
- People with intestinal and/or digestive disorders
- Heavy alcohol drinkers
- Pregnant women.
- Vegetarians and Vegans
Dietary Reference Intakes for vitamin B12:5
Infants (adequate intake)
0 to 6 months: 0.4 micro grams per day (mcg/day)
7 to 12 months: 0.5 mcg/day
1 to 3 years: 0.9 mcg/day
4 to 8 years: 1.2 mcg/day
9 to 13 years: 1.8 mcg/day
Adolescents and Adults
Males and females age 14 and older: 2.4 mcg/day
Pregnant teens and women: 2.6 mcg/day
Breastfeeding teens and women: 2.8 mcg/day
1. WHO/UNICEF/UNU. Iron deficiency anemia: assessment, prevention, and control. World Health Organization Geneva. 2001; (WHO/NDH/01.3)