Building and maintaining bone is complex work involving many nutrients, such as calcium, vitamin D, magnesium, boron, vitamin K, and essential fatty acids. A new study found that low levels of vitamins B6 and B12 and high levels of homocysteine were associated with increased risk of hip fracture.
B vitamins, homocysteine, and changes in bone
The study, published in the Journal of Clinical Endocrinology and Metabolism, included 714 senior men and women who were participating in the longstanding Framingham Study. Tests to measure bone density and blood levels of homocysteine, folic acid, and vitamins B6 and B12 were done at the beginning of the study and bone density was measured again after four years.
People with low vitamin B6 levels experienced more bone density loss than people with normal B6 levels, and people with B6 deficiency lost the most bone. Low and deficient levels of vitamins B6 and B12, as well as high levels of homocysteine (a potentially toxic amino acid byproduct), were each independently associated with more hip fractures.
How B vitamins and homocysteine are connected
Folic acid and vitamins B6 and B12 are all involved in the metabolism of homocysteine, and when any of these vitamin levels drops, homocysteine can accumulate, potentially leading to negative health effects. Getting more of these vitamins through diet or supplements can bring down high homocysteine levels. A high homocysteine level is a risk factor for heart disease, and some evidence suggests it might also be a risk factor for a number of other conditions including stroke, clotting problems, inflammatory bowel disease, Alzheimer’s disease, hypothyroidism, death from diabetes, pregnancy complications, and osteoporosis.
Despite their connection, B vitamins and homocysteine appear to have distinct effects on bone loss and fracture risk. “This study suggests that low vitamin B6 status, but not elevated homocysteine, is an important determinant of bone loss in community dwelling elders,” the study’s authors concluded.
Getting more B vitamins
The best way to get more vitamin B6 and folic acid is to eat plenty of fruits, vegetables, whole grains, and legumes. Vitamin B12 is found in animal foods and fish, and possibly sea vegetables and tempeh, a cultured soy food. Eating more of all three of these vitamins, especially folic acid, from food and supplements is a good strategy for reducing high homocysteine levels.
Although vitamin B6 and folic acid are usually readily absorbed, some health conditions can interfere with vitamin B12 absorption, such as gastritis, inflammatory bowel disease, infections of the digestive tract, and any condition that causes malabsorption. People with these conditions might need to take high-potency supplements and should consult their doctor first.
(J Clin Endocrinol Metab 2008;93:2206–12)
Maureen Williams, ND