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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #170051
Title: B VITAMINS AND PLASMA HOMOCYSTEINE CONCENTRATIONS IN AN URBAN AND RURAL AREA OF COSTA RICA

Author
item KIM, MI KYUNG - HARVARD SCH PUBLIC HLTH
item ORDOVAS, JOSE - TUFTS/HNRCA
item SELHUB, JACOB - TUFTS/HNRCA
item CAMPOS, HANNIA - HARVARD SCH PUBLIC HLTH

Submitted to: Journal of American College of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2002
Publication Date: 6/1/2003
Citation: Kim, M., Ordovas, J.M., Selhub, J., Campos, H. 2003. B vitamins and plasma homocysteine concentrations in an urban and rural area of costa rica. Journal of American College of Nutrition. 22(3):224-231.

Interpretive Summary: Homocysteine is an amino acid which plays important function but becomes harmful when its concentration in the blood becomes high. The blood level of homocysteine can be controlled by an appropriate intake of the vitamins folic acid, B6 and B12. In this study we measured vitamin blood levels and homocysteine in urban and rural areas of Costa Rica. We found that homocysteine levels were higher and plasma vitamin levels were lower in subjects from rural areas than subjects in urban areas. This was particularly true among women. Because high homocysteine is considered to be a risk for heart disease, this study justifies effort of implementation of food fortification program.

Technical Abstract: We studied the association between total plasma homocysteine (tHcy) concentrations and folate, B12, and B6 status in the urban and rural areas of Costa Rica. We determined plasma tHcy concentrations and assessed dietary folate, B12 and B6 intake by a food frequency questionnaire in 462 subjects selected by stratified random sampling in the urban and rural areas of Puriscal, Costa Rica. Plasma folate and vitamin B12 concentrations were measured in women. THcy concentrations were higher (p<0.01) in the rural compared with the urban area: 12.0 micromol/L vs. 8.9 micromol/L in men, and women 7.3 micromol/L vs. 5.5 micromol/L in women, respectively. The prevalence of hyperhomocysteinemia (greater than 15.0 micromol/L) was twice as high in rural compared with urban men (19.8% vs. 10.8%, p=0.06) and women (6.6% vs. 3.4%, p=0.26). Most study subjects (98%) had folate intakes that were less than the recommended 400 microg/day. In women, 31% of those living in the urban area and 40% of those in the rural area had plasma folate concentrations of less than 6.8 nmol/L, an indicator of folate deficiency. In women, age-adjusted mean tHcy concentrations (micromol/L) were higher in the lowest compared with highest quintiles for dietary vitamin B6 (9.9 vs. 5.4, p<0.05), B12 (9.2 vs. 4.9, p<0.01), and folate (7.0 vs. 5.7, p=0.87). Similar results were found for plasma B12 (9.9 vs. 5.4, p<0.01) and folate (10.5 vs. 5.0, p<0.0001). Residents of the rural area in Puriscal, Costa Rica have higher plasma concentrations of tHcy and lower intake of B vitamins, particularly in women. Because these characteristics are associated with high risk of cardiovascular disease, the efficacy of food fortification program in rural areas should be carefully addressed.