Blood Donation, Being Asian, and a History of Iron Deficiency Are Stronger Predictors of Iron Deficiency than Dietary Patterns in Premenopausal Women

Table 1

Characteristics of study subjects with and without suboptimal iron status.

Characteristic	Subjects with sufficient iron stores (𝑛=305)^a	Subjects with suboptimal iron status (𝑛=70)^b	𝑃 value^c
Age (year)	27.5±8.4	30.1±9.0	0.02
BMI (kg/m^2)	23.5±4.1	23.0±3.2	0.35
SF (𝜇g/L)	52.9±27.0	13.0±4.3	<0.001
Hb (g/L)	133.7±8.0	124.9±10.5	<0.001
Ethnicity
European	239 (78.6)	43 (61.4)	0.002
Asian	36 (11.8)	20 (28.6)
Other	29 (9.5)	7 (10.0)
Born in New Zealand	177 (58.2)	35 (50.0)	0.23
Having children	80 (26.3)	32 (45.7)	0.002
Any blood donation in the past year	24 (7.9)	19 (27.1)	<0.001
Having nose bleeds	30 (9.9)	8 (11.4)	0.83
Estimated menstrual blood loss (blood loss units)	39.0±31.5	45.8±32.8	0.137
Duration of menstrual period (d)	4.9±1.4	5.4±1.4	0.004
Using oral contraception	99 (32.7)	12 (17.1)	0.013
Using intrauterine device^d	17 (5.6)	2 (2.9)	0.547
Used low dose iron supplements or multivitamins in the past year	87 (28.7)	21 (30.0)	0.88
Previous iron deficiency	116 (38.2)	39 (55.7)	0.01
Smoker^d	21 (6.9)	3 (4.3)	0.591

Data are mean ± standard deviation or 𝑛 (%).
aSF ≥ 20 𝜇g/L and Hb ≥ 120 g/L.
^bSF < 20 𝜇g/L (Hb < 120 or ≥120 g/L).
^c𝑃 value is for a test of differences between groups as assessed by the independent 𝑡-test (continuous data) or chi-square test (categorical data) (adequate expected values).
^dDifference between groups assessed using Fisher’s exact test as expected values <5.0.
BMI: body mass index; Hb: hemoglobin; SF: serum ferritin.