Calcium, vitamin D and dairy intake in relation to type 2 diabetes risk in a Japanese cohort

Abstract

Aims/hypothesis Calcium and vitamin D have been implicated in the development of type 2 diabetes, but epidemiological evidence is limited. We examined prospectively the relation of calcium and vitamin D intake to type 2 diabetes risk in a Japanese cohort. Methods Participants were 59,796 middle-aged and older men and women, who participated in the Japan Public Health Center-based Prospective Study and had no history of type 2 diabetes or other serious diseases. Dietary intake of calcium and vitamin D were estimated using a validated food frequency questionnaire. Logistic regression was used to assess the association between intake of these nutrients and self-reported newly diagnosed type 2 diabetes. Results During a 5 year follow-up, 1,114 cases of type 2 diabetes were documented. Overall, calcium intake was not associated with a significantly lower risk of type 2 diabetes; the multivariable odds ratio for the highest vs lowest quartiles was 0.93 (95% CI 0.71-1.22) in men and 0.76 (95% CI 0.56-1.03) in women. However, among participants with a higher vitamin D intake, calcium intake was inversely associated with diabetes risk; the odds ratio for the highest vs lowest intake categories was 0.62 (95% CI 0.41-0.94) in men and 0.59 (95% CI 0.38-0.91) in women. Dairy food intake was significantly associated with a lower risk of type 2 diabetes in women only. Conclusions/interpretation Calcium and vitamin D may not be independently associated with type 2 diabetes risk. Our finding suggesting a joint action of these nutrients against type 2 diabetes warrants further investigation.

Dairy consumption and risk of type 2 diabetes mellitus: a meta-analysis of cohort studies

“…A total of seven publications with cohort studies (Choi et al, 2005;Liu et al, 2006;Pittas et al, 2006;van Dam et al, 2006;Elwood et al, 2007;Kirii et al, 2009;Villegas et al, 2009) on dairy and milk consumption and T2DM were included according to the criteria (Table 1). In the study by Kirii et al (2009), participants were divided to men and women for observation.…”

“…In the study by Kirii et al (2009), participants were divided to men and women for observation. Thus, it was considered two studies when the observed items were combined.…”

“…Thus, it was considered two studies when the observed items were combined. Among these studies, dairy products appeared as items in six studies (Choi et al, 2005;Liu et al, 2006;Pittas et al, 2006;van Dam et al, 2006;Elwood et al, 2007;Kirii et al, 2009), low-fat and high-fat dairy foods appeared in three studies (Choi et al, 2005;Liu et al, 2006;van Dam et al, 2006), whole milk appeared in four studies (Choi et al, 2005;Liu et al, 2006;Kirii et al, 2009;Villegas et al, 2009) and yogurt appeared in three studies (Choi et al, 2005;Liu et al, 2006;Kirii et al, 2009). …”

Dietary calcium intake and risk of type 2 diabetes: possible confounding by magnesium

“…The number of cases ranged from 199 to 4843, and the cohort sizes ranged from 5200 to 83 779. Four studies included women only, whereas two studies enrolled both men and women, of which one 5 reported separate results by sex. The length of follow-up ranged from 5 to 20 years.…”

Solar radiation and human health

“…A cohort study in The Netherlands found an odds ratio of 0.28 (95% CI, 0.10-0.81) for >75 nmol l −1 versus <25 nmol l −1 (males) but no effect for females [453]. A cohort study in Japan found an odds ratio of 0.62 (95% CI, 0.41-0.94) for males and 0.59 (95% CI, 0.38-0.91) for females for highest versus lowest calcium intake with higher vitamin D intake [454].…”