UK women of childbearing age falling short on key micronutrient requirements, survey finds

13 Aug 2018 --- The micronutrient intake of women in their childbearing years, as well as young people in general, fall short in key micronutrients such as magnesium and selenium. UK researchers note that improvements in dietary quality are needed in young adulthood and mid-life. Alongside this, fortification and supplementation strategies may be considered to help adults achieve dietary targets at this life-stage when they should be at their “nutritional prime.”

The secondary analyses of the UK National Diet and Nutrition Survey highlights how there is a tendency to report micronutrients intakes collectively for adults, with broad age ranges being used. This means that certain sub-population groups such as young adults are often overlooked. The current analysis sought to focus on such subpopulations.

“Younger adults and females appear to be particularly vulnerable to micronutrient shortfalls from food sources alone. Clearly, improvements in dietary quality are needed across mid-life stages. Alongside this, supplementation strategies should be considered to help adults achieve dietary targets at this life-stage when they should be at their nutritional peak,” says Dr. Emma Derbyshire, Public Health Nutritionist and an advisor to the Health & Food Supplements Information Service (HSIS).

The secondary analysis noted sizeable gaps for magnesium in both men and women, with 19 percent of young people in their twenties having intakes below the Lowest Recommended Nutrient Intake (LRNI). There were also considerable gender gaps in dietary selenium intakes, with 50.3 percent females and 25.8 percent of males having total intakes beneath the LRNI. 

Selenium has been highlighted as a crucial nutrient for women seeking to become pregnant. By increasing their risk of preeclampsia, mothers with low selenium levels may also be at increased risk for heart disease, stroke and high blood pressure later in life, according to a Cypress Systems executive summary. The summary calls for higher levels of supplementation of high selenium yeast to combat heart health threats.

Furthermore, a quarter of women had iron (25.3 percent) and potassium (24.3 percent) intakes below the LRNI, while among UK males, vitamin A and zinc shortfalls were apparent. 

The researchers say that an adequate micronutrient profile for women is not only important for fertility but also to prepare the body for the extensive physiological demands should pregnancy occur. Nutritional intakes in mid-life can help to future-proof health against debilitating and chronic diseases that can occur in later life.

Why do so many young adults have insufficient micronutrient intakes?
Researchers noted that regarding women’s nutritional shortfalls, societal pressures around body image could be a factor. They cite a recent survey of 1,035 social media tweets typically used by young adults that found that 67.2 percent related to body image, eating disorders, fitness, food or dieting. This, in turn, could have wider ramifications impacting on dietary habits and micronutrient profiles of young women. Emerging food trends and the avoidance of food groups could be impacting on micronutrient intakes, they add. For example, the consumption of eggs, milk, and dairy correlates strongly against female nutritional iodine status while veganism has also been found to impact on vitamin D, calcium and vitamin B12, iodine and selenium intakes. They further add that UK females having diets lower in red meat (<40 g daily) have reduced micronutrient intakes, especially zinc and vitamin D.

In terms of the low vitamin A intake of males, the researchers highlight research that indicates that males men's mean intakes of fruit and vegetables were slightly lower at 3.9 portions daily compared with 4.1 portions daily among women aged 19 to 64 years. It has also been found that fruit and vegetable variety tends to be lower in men, especially in instances where education and social class is lower.

Turning to zinc, this micronutrient is a known antioxidant with research showing that fertile males tend to have higher seminal zinc levels than their infertile counterparts. Zinc also has important catalytic, structural, and regulatory roles helping to support immunity and avert age-related diseases. Zinc shortfalls are somewhat surprising to see, the researchers add, especially among males, given that meat and meat products are one of the main providers of zinc. It is possible that younger men in their twenties are eating less meat which could have contributed to lower zinc intakes in this age group, the researchers note. This is an important finding and worthy of consideration in the context of public health given current trends toward plant-based diets, they explain.

“It is imperative to continue raising awareness about the importance of healthy and balanced diets and adequate micronutrient intakes. The implications of ‘cutting back or cutting out’ certain food groups also need to be communicated, especially to younger generations who are strongly influenced by social media which is not subject to peer review or monitoring systems,” says Derbyshire.

How can the industry respond?
The current research found that females and young adults are at particular risk of micronutrient shortfalls. In an environment, where the public are being encouraged to reduce their energy intakes, it is important to ensure that the micronutrient profile of diets is sustained, the researchers note.

They add that the role of multivitamin and mineral supplements and value of daily compliance also warrants practical consideration. For example, in the UK there is a Government health message to supplement with 10μg vitamin D between autumn and spring to protect bone and muscle health.

The researchers also stress that the role of food fortification strategies should not be overlooked in the context of today’s modern lifestyles. In the US, for example, the strategy is to fortify food with folic acid which directly benefits the micronutrient profile of women of childbearing age.

By Laxmi Haigh