A randomized double blind controlled trial was conducted to evaluate the effect of daily supplementation with soy isoflavone 100 mg/day for 12 months on 182 postmenopausal women aged 47 to 60 years at subdistrict South Jakarta Indonesia. The study hypothesis was supplementation soy isoflavone 100 mg/day for 6 and 12 months can increase endothelial function.

The subject were randomized to the intervention group receiving tablets consisting of 100 mg soy isoflavone and calcium carbonate 500 mg and the control group receiving 500 mg calcium carbonate for 1 year. This study was carried out 13 months(13 x 28 days).

There were three outcome measure from this study; vascular cell adhesion molecule-(VCAM-1), nitric oxide (NO) and malonyldialdehyde (MDA). The outcome measure will be assessed at three times; before soy isoflavone supplementation / the beginning of study,post supplementation 6 months and 12 months. The outcome will be measured change from baseline in the level of VCAM-1, NO and MDA.

Inclusion Criteria:

• healthy postmenopausal women
• natural cessation 1-10 years
• body mass index <=35 kg/m2
• not receiving medication and supplement in the previous 6 months

Exclusion Criteria:

• has chronic or terminal disease
• severe psychosis