Low dietary vitamin D in mid-life predicts total mortality in men with hypertension: the Honolulu heart program.
BACKGROUND
Vitamin D deficiency was associated with total mortality in previous epidemiological studies. Little is known about the effects of dietary vitamin D intake on mortality. We examined the association between mid-life dietary vitamin D intake and 45-year total mortality.


METHODS
The Honolulu Heart Program is a longitudinal cohort study of 8006 Japanese American men in Hawaii aged 45 to 68 at baseline (1965-1968). Mid-life dietary vitamin D intake was calculated from 24-hour dietary recall using Nutritionist IV v3 software. We divided subjects into quartiles of dietary vitamin D. Total mortality data were available over 45 years through 2010.


RESULTS
Age-adjusted total mortality rates were higher in the lower quartiles of dietary vitamin D intake compared to the highest (p for trend = 0.011). Using Cox regression, low dietary vitamin D was significantly associated with total mortality; quartile (Q) 1 hazard ratio (HR) = 1.14, 95% confidence interval (95% CI) = 1.07-1.22, p < 0.001; Q2 HR = 1.11, 95% CI = 1.04-1.18, p = 0.002; and Q3 HR = 1.08, 95% CI = 1.01-1.15, p = 0.027; Q4 = reference. After adjusting for age, kilocalories, cardiovascular risk factors, and prevalent chronic diseases, only Q2 remained significant (HR = 1.08, 95% CI = 1.00-1.15, p = 0.037). Among hypertensive subjects only, those in the lower 2 quartiles had higher total mortality; Q1 HR = 1.12, 95% CI = 1.01-1.25, p = 0.039, and Q2 HR = 1.13, 95% CI = 1.02-1.26, p = 0.025, compared to Q4. There was no significant relationship in subjects without hypertension.


CONCLUSIONS
Low dietary vitamin D intake in mid-life was a weak predictor of total mortality over 45 years of follow-up. We found a significant association between low dietary vitamin D intake and higher total mortality only among hypertensive subjects. Vitamin D may have cardioprotective effects.
a The John A. Hartford Foundation Center of Excellence in Geriatrics, Department of Geriatric Medicine, John A. Burns School of Medicine, University of Hawaii.
Gotaro
G
Kojima
Christina L
CL
Bell
Randi
R
Chen
G Webster
GW
Ross
Robert D
RD
Abbott
Lenore
L
Launer
Felix
F
Lui
Kamal
K
Masaki
D000368:Aged; D000369:Aged, 80 and over; D001213:Asian; D015331:Cohort Studies; D004032:Diet; D006254:Hawaii; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000401:mortality*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014807:Vitamin D / Q000008:administration & dosage*; D014808:Vitamin D Deficiency / Q000150:complications / Q000401:mortality*
D014807:Vitamin D
Asian Americans; Japan/ethnology; hypertension; mortality; vitamin D