Speaking to NutraIngredients, Alexandra Purdue-Smithe from the department of Biostatistics & Epidemiology at the University of Massachusetts Amherst, said: “Because early menopause is associated with higher risk of cardiovascular disease, early cognitive decline, osteoporosis and other health problems, identifying easily modifiable risk factors for early menopause, such as vitamin D and calcium intake, is important for women of reproductive age to reduce their risk.”
The study involved 116,430 female US registered nurses who were aged between 25 and 42 in 1989 when they responded to a questionnaire.
Subsequently, intake of vitamin D and calcium from foods and supplements were measured every four years and lifestyle behaviours and medical conditions monitored every two years.
In total, 2,041 women reported having natural menopause before the age of 45.
The study authors then evaluated relations between intake of vitamin D and calcium and incidents of early menopause while accounting for possible confounding factors.
Study results
The results found that women with the highest intake of dietary vitamin D had a 17% lower risk, marked as significant, of early menopause compared to women with the lowest intake of dietary vitamin D.
Additionally, the research found that those that took the highest intake of dietary calcium were linked to a “borderline significantly lower risk” of early menopause compared with the lowest intake.
The study also found that associations were stronger for vitamin D and calcium from dairy sources than from non-dairy dietary sources, whereas high supplement intake was not associated with lower risk.
The findings suggest that high intakes of dietary vitamin D and calcium may be “modestly associated” with lower risk of early menopause.
“I think this study is significant in that it raises some very interesting directions for future research,” Purdue-Smithe told us.
“The inverse associations we observed for dietary intake of vitamin D and calcium were particularly strong for dairy sources of these nutrients."
This raises two questions. Is what we’re seeing here truly due to vitamin D or is there something else about diary that is driving the association?”
Further research into dairy
Purdue-Smithe said further studies were now being undertaken.
“We're currently working on two additional projects to evaluate blood levels of vitamin D and risk of early menopause and to evaluate intake of individual dairy foods and dairy constituents and risk of early menopause.
“Findings from these studies will give us a better idea of how to answer these two questions,” she told us.
Source: The American Journal of Clinical Nutrition
Published online ahead of print: DOI:10.3945/ajcn.116.145607
“Vitamin D and calcium intake and risk of early menopause.”
Authors: Alexandra C Purdue-Smithe et al