Sunday, July 26, 2015
Monday, July 6, 2015
Know Vitamin B12
Vitamin B12(cobalamin)
·
water soluble vitamin
·
commercially available as cyanocobalamin(most stable form)
Dietary Source: animal protein products
The
best sources of vitamin B12 include the following.
·
Liver
·
Kidney
·
Milk
·
Eggs
·
Fish
·
Cheese
In stomach
b12 + intrinsic factor(secreted from parietal cells of gastric mucosa)
= IF-b12 complex -------------------------; binds with speccific
receptor on ileal mucosal cells-------------; circulation
In
the circulation, vitamin B12 binds to the plasma globulin transcobalamin II for
transport to cells(where it carries out its metabolic function), or to the
liver, where it is stored until it is needed by other tissues.
Because
the liver can store 1 to 10 mg of vitamin B12, and vitamin B12 can be
reabsorbed from the bile in the enterohepatic circulation, strict vegetarians
who eat little or no animal products may only gradually (after 20 to 30 years)
develop any vitamin B12 deficiency.
Vitamin
B12 is an essential coenzyme for the normal function of all cells. It
affects cell growth and replication.
Active
coenzyme forms
·
5-deoxyadenosylcobalamin
·
methylcobalamin.
Causes
for vitamin B12 deficiency
·
seen
today are not due to a dietary deficiency but to inadequate absorption.
·
Gastric
atrophy or gastric surgery can inhibit the secretion of IF and lead to vitamin
B12 deficiency.
·
Gastric
atrophy is a common cause of vitamin B12 deficiency in the elderly as it is a
progressive, genetically determined, age-dependent disease that occurs as a
person ages.
·
Less
common etiologies of vitamin B12 deficiency are pancreatic disorders, which
affect the secretion of pancreatic enzymes that are needed to release vitamin
B12 from salivary proteins (so that it can bind to IF), and a congenital
absence of transcobalamin II.
Dosage
Ranges and Duration of Administration
The
RDA for vitamin B12 is as follows.
·
Neonates
to 6 months.: 0.3 mcg
·
Infants
6 months to 1 year: 0.5 mcg
·
Children
1 to 3 years: 0.7 mcg
·
Children
4 to 6 years: 1.0 mcg
·
Children
7 to 10 years: 1.4 mcg
·
Men
age 11 years and over: 2.0 mcg
·
Women
age 11 years and over: 2.0 mcg
·
Pregnant
women: 2.2 mcg
·
Lactating
women: 2.6 mcg
Subscribe to:
Posts (Atom)
Management of Insomnia/Sleeplessness through Integrative medicine approach
Overview Definition Insomnia is a disorder or a symptom of another condition, not a disease. It is the persistent inability or difficulty...
-
Vitamin B12 (cobalamin) · water soluble vitamin · commercially available as cyanocobalamin (most stable form) ...
-
Relationship of Body, Mind and Consciousness. Positive relationship with body, mind and consciousness. Healthy Body can develop ...
-
Overview Definition Insomnia is a disorder or a symptom of another condition, not a disease. It is the persistent inability or difficulty...