NEW YORK (Reuters Health) - Compared with healthy women, those with rheumatoid arthritis are deficient in vitamin B6 and have elevated levels of homocysteine, a type of amino acid that has been linked to heart attacks and strokes, new research shows.

The vitamin B6 deficit appears to be the result of altered metabolism, not reduced dietary intake, according to the report in the Journal of the American Dietetic Association. The results also indicate that as vitamin B6 levels drop and homocysteine levels rise, disability status worsens.

Numerous reports have shown that rheumatoid arthritis patients are at risk for early death from cardiovascular disease, the authors point out. The reason for the elevated risk, however, is unclear since there is evidence that traditional cardiovascular risk factors, such as high cholesterol levels, are no more common in arthritis patients than in healthy individuals.

Furthermore, through mechanisms that are unclear, homocysteine increases the risk of cardiovascular disease. Findings from several studies have indicated that homocysteine metabolism is altered with rheumatoid arthritis, which may in turn relate to changes in how vitamin B6 is processed. Typically as vitamin B6 levels fall, homocysteine levels increase.

Prior research has shown low levels of vitamin B in rheumatoid arthritis patients, co-authors Dr. Kathleen Woolf and Dr. Melinda M. Manore comment, but the studies did not provide adequate information to determine whether this was simply a result of low vitamin B levels in the diet.

The present findings, derived from a study of 18 patients and 33 healthy subjects, indicate that dietary levels of B vitamins are not decreased in rheumatoid arthritis patients, yet they still show a deficit of vitamin B6. Consistent with this finding, rheumatoid arthritis was also associated with increased levels of homocysteine. None of the subjects in the study were using B vitamin supplements.

In agreement with some earlier studies, levels of total cholesterol and "bad" LDL cholesterol were actually lower in patients than in healthy individuals.

"When registered dietitians are working with individuals with rheumatoid arthritis, they should assess B-vitamin status and...homocysteine concentrations," emphasize Woolf, from Arizona State University in Mesa, and Manore, from Oregon State University in Corvallis.

"Individuals with rheumatoid arthritis may need to get more B vitamins through diet, supplements, or fortified foods. Foods that are especially high in vitamin B6 are meats, fish, poultry, legumes, non-citrus fruits, fortified cereals, and soy products."