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Vitamine
B12 tegen botontkalking.*
Vrouwen hebben 4x zoveel kans op osteoporosis dan mannen. Een
wetenschappelijk onderzoek nu toont een duidelijk verband aan tussen (te) lage
waarden vitamine B12 en de hogere mate van botontkalking. Iedereen van de ruim
2500 deelenemers aan de studie met een te lage bloedwaarde vitamine B12 had een
duidelijk lagere minerale dichtheid van de botten. Het hoe en waarom is nog niet
bekend. Vitamine B12 zit hoofdzakelijk in dierlijke producten zoals vis, rood
vlees, yoghurt en kaas. Vooral ouderen boven de 50 hebben beduidend meer kans op
lage waarde door o.a. minder maagzuurproductie en een gebrek aan de intrinsieke
factor in de maag, nodig om B12 op te kunnen nemen.
Fight Osteoporosis: Bone Up On
B12
Women are about four times
more likely than men to develop osteoporosis, or weak, porous bones. But a new
study links vitamin B12 deficiency with low bone mineral density in men, and
confirms similar, previously reported findings in women.
Researchers funded by the
Agricultural Research Service (ARS) reported the findings in the Journal of Bone
and Mineral Research. The study was led by epidemiologist Katherine Tucker with
the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts
University in Boston, Mass. Tucker directs the HNRCA's Dietary Assessment and
Epidemiology Research Program.
While vitamin B12 deficiency
has been linked with low levels of markers of bone formation, the mechanism
behind the relationship is not known.
The scientists examined the
relationship between vitamin B12 blood levels and indicators of bone health
measured in 2,576 men and women, aged 30 to 87, participating in the Framingham
Osteoporosis Study. They found that those with vitamin B12 levels lower than 148
picomoles per liter (pM/L) were at greater risk of osteoporosis than those with
higher levels. Plasma B12 levels below 185 pM/L are considered "very
low," according to some experts.
The study found that those
with vitamin B12 concentrations below 148 pM/L had significantly lower average
bone mineral density--at the hip in men, and at the spine in women--than those
with concentrations above.
The range of symptoms of B-12
deficiency includes anemia, balance disturbances and cognitive decline.
Osteoporosis usually progresses with no outward effect until a fracture occurs.
The recommended dietary
allowance for vitamin B12 is 2.4 micrograms per day for both men and women. Low
stomach acid and aging can lower the ability to absorb the vitamin. Those over
age 50 are encouraged to consume fortified foods or supplements containing B12.
This study suggests adequate
vitamin B12 intake is important for maintaining bone mineral density. Animal
protein foods, such as fish, liver, beef, pork, milk and cheese are good sources
of vitamin B12.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.