Table 1.

Descriptive characteristics of men and women in the Framingham Study at baseline who had measures of at least one plasma measure (folate, vitamin B12, vitamin B6, or homocysteine) and BMD (1987–1989), according to whether they had a follow-up BMD measurement (1991–1993)

Characteristica	All participants	Baseline and follow-up	Baseline only
No.	1002	714	288
% Women	60.2	63.8	53.8
Age (yr)	75.3 ± 4.9	74.5 ± 4.5	77.3 ± 5.6
Height (in.)	63.7 ± 3.8	63.7 ± 3.7	63.8 ± 75.3
Weight (lb)	154.8 ± 31.4	155.8 ± 31.9	152.4 ± 29.8
% Current cigarette smoker	10.3	9.9	11.5
Physical activity index	33.5 ± 59.5	33.9 ± 5.4	32.5 ± 5.2
Alcohol (oz/wk)	2.3 ± 3.7	2.3 ± 3.7	2.2 ± 3.7
Caffeine (% more than two cups/d)	24.3	24.1	24.7
% Current estrogen use in women	4.6	5.6	1.9
Calcium intake (mg/d)	800.9 ± 428.5	798.6 ± 423.7	807.2 ± 442.3
25(OH)D (ng/ml)	29.6 ± 12.3	30.0 ± 12.0	28.7 ± 12.8
Baseline femoral neck BMD (g/cm2)	0.780 ± 0.142	0.787 ± 0.139	0.765 ± 0.148
Folate (nmol/liter)
% Normal (≥11)	43.3	43.0	43.9
% Low (7–10.9)	21.5	22.7	18.7
% Deficient (<7)	35.2	34.3	37.4
Vitamin B12 (pmol/liter)
% Normal (≥258)	61.0	60.2	62.9
% Low (148–257.9)	27.8	29.1	24.6
% Deficient (<148)	11.2	10.7	12.5
Vitamin B6 (nmol/liter)
% Normal (≥30)	76.6	78.4	72.2
% Low (20–29.9)	11.8	11.2	13.1
% Deficient (<20)	11.6	10.4	14.7
Homocysteine (μmol/liter)
% Normal (≤14)	73.7	76.7	66.6
% High (>14)	26.3	23.3	33.4

^aMean ± sd unless otherwise noted.