Table 1.

Baseline Demographic and Clinical Characteristics of Adults Aged 60–90 Years in a 6-Week Trial of Folic Acid Supplementation and Change in Serum Folate and Plasma Homocysteine Concentrations, by Folic Acid Dose Group, Baltimore, Maryland, 1996^a

	All Participants (n = 133)			Placebo Group (0 μg/day) (n = 26)			Folic Acid Supplement Dose, μg/day
							100 (n = 27)			400 (n = 27)			1,000 (n = 26)			2,000 (n = 27)
	No.	%	Median (IQRb)	No.	%	Median (IQR)	No.	%	Median (IQR)	No.	%	Median (IQR)	No.	%	Median (IQR)	No.	%	Median (IQR)
Demographic factors
Female sex	93	70		21	81		21	78		17	63		17	65		17	63
Black race	20	15		2	8		6	22		6	22		4	15		2	7
Current smoker	9	7		3	12		0	0		2	7		1	4		3	11
Prior multivitamin user	41	31		7	27		7	26		8	30		9	35		10	37
Age, years			76 (71–81)			75.5 (73–84)			75 (69–80)			76 (69–82)			75.5 (71–81)			77 (72–80)
Clinical characteristics
Body mass indexc			27.1 (24.2–30.1)			26.0 (22.5–27.8)			27.7 (24.8–31.1)			27.1 (24.2–31.3)			27.4 (25.4–30.8)			27.4 (24.0–31.6)
Dietary folate intake, μg/day			282 (221–349)			310 (248–417)			244 (195–309)			289 (221–341)			281 (206–364)			302 (184–388)
Alcohol consumption, drinks/week			0 (0–1)			0 (0–1)			0 (0–2)			0 (0–1)			0 (0–2)			0 (0–2)
Serum vitamin B12 concentration, pg/mL			407 (308–480)			425 (294–477)			393 (308–526)			423 (315–475)			356 (305–493)			424 (357–471)
Serum creatinine concentration, mg/dL			1.0 (0.8–1.2)			1.0 (0.8–1.0)			0.9 (0.8–1.1)			1.1 (0.9–1.2)			1.0 (0.9–1.2)			0.9 (0.8–1.1)
Estimated glomerular filtration rated, mL/minute/1.73 m2			65 (58–75)			65 (57–75)			73 (57–81)			65 (57–76)			64 (57–72)			72 (59–79)

Abbreviation: IQR, interquartile range.

^aThere were no statistically significant differences among groups at baseline with regard to demographic factors, clinical characteristics, or outcome variables (P > 0.05).

^b25th–75th percentiles.

^cWeight (kg)/height (m)².

^dCalculated using the Modification of Diet in Renal Disease Study (28) 4-variable simple equation variables (P > 0.05).