Are plasma mineral levels related to antibody response to influenza vaccination in older adults?

Figures & data

Table 1. Baseline Demographic Characteristics and Mineral Levels at Day 0 and Day 21.

Variable		n (%)		n (%)
Race	Non-white	48 (44)	White	61 (56)
Sex	Male	31 (28)	Female	78 (72)
Diabetes	Yes	39 (36)	No	70 (64)
Overweight (BMI ≥25)	Yes	88 (81)	No	21 (19)
Age, years, mean (SD)		62.6 (7.2)
BMI, mean (SD)		32.0 (7.5)
Mineral level	Day 0 Mean (SD)		Day 21 Mean (SD)		Normal values
Copper	21 (4) µmol/L		21 (6) µmol/L		12.5–21.0 µmol/L
Iron	2.14 (0.90) mg/L^*		2.24 (3.36) mg/L^*		0.5–1.7 mg/L
Potassium	3.17 (0.83) mEq/L		4.15 (1.88) mEq/L		3.5–5.4 mEq/L
Magnesium	1.4 (0.2) mEq/L^**		1.40 (0.19) mEq/L^**		1.5–2.4 mEq/L
Phosphorus	5.71 (0.88) mEq/L^*		6.0 (1.2) mEq/L^*		2.5–4.5 mg/dL
Zinc	12 (6) µmol/L		16 (15) µmol/L		9–16 µmol/L
Cu/Zn ratio	1.87 (0.75) µmol/L		1.67 (0.68) µmol/L		—

Notes. BMI=weight/height² (kg/m²).

* Above normal range.

** Below normal range.

Table 2. Relationship of Mineral Levels at Day 0 to Immune Response to Influenza Vaccine, Adjusted for Race.

	Antibody Titers for H1N1
	Seroprotection (≥40) at Day 21			Seroconversion (4-fold rise) at Day 21
Mineral level (log2) at Day 0	Odds ratio	95% CI	P value	Odds ratio	95% CI	P value
Zinc	1.87	0.53–6.58	0.33	0.64	0.15–2.65	0.54
Copper	1.07	0.24–4.68	0.93	2.19	0.39–12.24	0.37
Phosphorus	1.37	0.24–7.75	0.72	2.35	0.31–17.7	0.41
Magnesium	1.41	0.18–11.08	0.75	3.36	0.29–38.82	0.33
Potassium	1.15	0.38–3.47	0.80	0.58	0.17–1.96	0.38
Iron	1.48	0.70–3.10	0.30	1.02	0.45–2.34	0.96
Copper/Zinc ratio	0.80	0.43–1.49	0.47	1.65	0.83–3.30	0.15
Multivariate model including obesity
Copper	—	—	—	8.41	1.21–58.5	0.03
Phosphorus	—	—	—	7.58	1.38–41.7	0.02
Magnesium	—	—	—	15.00	1.13–198.8	0.04
	Antibody Titers for H3N2
	Seroprotection (≥40) at Day 21			Seroconversion (4-fold rise) at Day 21
Mineral level (log2) at Day 0	Odds ratio	95% CI	P value	Odds ratio	95% CI	P value
Zinc	1.49	0.40–5.46	0.55	1.50	0.41–5.54	0.55
Copper	0.81	0.17–3.75	0.78	1.64	0.34–7.87	0.54
Phosphorus	1.42	0.24–8.50	0.70	3.95	0.61–25.80	0.15
Magnesium	1.60	0.19–13.54	0.67	7.56	0.76–75.5	0.09
Potassium	2.35	0.76–7.29	0.14	1.57	0.47–5.20	0.46
Iron	0.52	0.24–1.12	0.09	0.41	0.18–0.95	0.04
Copper/Zinc ratio	0.73	0.38–1.40	0.35	1.05	0.55–2.02	0.88

Table 3. Relationship of Day 21 Mineral Levels to Immune Response to Influenza Vaccine, Adjusted for Race.

	Antibody Titers for H1N1
	Seroprotection (≥40) at Day 21			Seroconversion (4-fold rise) at Day 21
Mineral level (log2) at Day 21	Odds ratio	95% CI	P value	Odds ratio	95% CI	P value
Zinc	4.07	1.02–16.20	0.05	1.52	0.34–6.71	0.58
Copper	2.16	0.48–9.79	0.32	10.09	1.50–68.07	0.02
Phosphorus	6.15	1.56–24.23	0.01	7.28	1.40–37.90	0.02
Magnesium	1.04	0.15–7.43	0.97	14.22	1.26–160.44	0.03
Potassium	1.45	0.72–2.89	0.30	1.95	0.91–4.22	0.09
Iron	1.37	0.75–2.48	0.30	1.07	0.54–2.10	0.86
Copper/Zinc ratio	0.79	0.39–1.60	0.51	1.25	0.57–2.73	0.58
Potassium, difference Day 0 to Day 21	1.21	0.70–2.11	0.50	1.71	0.94–3.11	0.08
Phosphorus, difference Day 0 to Day 21	7.10	1.59–31.8	0.01	5.65	0.99–32.17	0.051
Iron difference, Day 0 to Day 21	1.04	0.60–1.81	0.89	1.05	0.56–1.99	0.87
Multivariate models including Magnesium, Phosphorus, Copper:
Phosphorus	5.64	1.46–21.86	0.01	6.63	1.25–35.10	0.03
Copper	—	—	—	7.68	1.24–47.42	0.03
Multivariate models including Magnesium, Phosphorus, Copper/Zinc: ratio
Phosphorus	6.69	1.61–27.86	0.01	—	—	—
	Antibody Titers for H3N2
	Seroprotection (≥40) at Day 21			Seroconversion (4-fold rise) at Day 21
Mineral level (log2) at Day 21	Odds ratio	95% CI	P value	Odds ratio	95% CI	P value
Zinc	2.04	0.51–8.20	0.32	0.63	0.16–2.48	0.51
Copper	2.45	0.51–11.78	0.26	3.99	0.77–20.68	0.10
Phosphorus	4.16	1.06–16.32	0.04	7.27	1.61–32.92	0.01
Magnesium	0.75	0.10–5.80	0.79	3.94	0.47–32.78	0.21
Potassium	0.94	0.47–1.89	0.86	0.88	0.43–1.81	0.73
Iron	1.49	0.80–2.78	0.21	1.00	0.54–1.85	1.00
Copper/Zinc ratio	0.82	0.39–1.70	0.59	1.38	0.67–2.86	0.38
Potassium, difference Day 0 to Day 21	0.80	0.46–1.39	0.43	0.86	0.48–1.53	0.60
Phosphorus, difference Day 0 to Day 21	4.38	0.99–19.49	0.52	3.90	0.83–18.34	0.08
Iron, difference Day 0 to Day 21	2.19	1.16–4.15	0.16	1.66	0.90–3.07	0.11
Multivariate models including Magnesium, Phosphorus, Copper:
Phosphorus	3.86	1.00–14.86	0.05	7.47	1.66–33.58	0.01
Multivariate models including Magnesium, Phosphorus, Copper/Zinc ratio:
Phosphorus	—	—	—	6.13	1.35–27.80	0.02

Table A1. Relationship of Day 0 Mineral Levels to Influenza Vaccine Antibody Titers at Day 0 (baseline).

	Seroprotection (≥40) at Day 0 for A/H1N1			Seroprotection (≥40) at Day 0 for A/H3N2
Mineral level (log2) at Day 0	Odds ratio	95% CI	P value	Odds ratio	95% CI	P value
Zinc	1.31	0.35–4.89	0.69	1.46	0.36–5.97	0.60
Copper	0.35	0.07–1.68	0.19	0.95	0.19–4.81	0.95
Phosphorus	0.99	0.16–6.02	0.99	0.15	0.02–1.11	0.06
Magnesium	1.12	0.13–9.78	0.92	0.62	0.06–6.04	0.68
Potassium	1.09	0.35–3.41	0.89	2.34	0.65–8.45	0.20
Iron	1.59	0.75–3.40	0.23	0.66	0.29–1.48	0.31
Copper/Zinc ratio	0.71	0.36–1.42	0.34	0.81	0.40–1.64	0.55