Specifically, zinc concentrations dropped 6.6% from the early follicular phase (around menstruation) to the mid-luteal phase, raising zinc deficiency prevalence from 22% to 37% from the start to the end of the menstrual cycle.
Magnesium levels fell 4.5% from the early follicular phase to the mid-luteal phase. The prevalence of magnesium deficiency was even more shocking, increasing from 29% during the early follicular phase to 49% during the mid-luteal phase. In other words, approximately half of participants were deficient in magnesium between ovulation and menstruation.
Ferritin levels (aka iron stores) dropped the most following menstrual bleeding (i.e., between the early and late follicular phases), decreasing 15.2%. Due to the lagging body stores of iron, ferritin concentrations continued to drop 5.5% between the late follicular phase and the mid-luteal phase, causing a 19.8% decrease from the start of the menstrual cycle to the end.
Other micronutrients that were tested during the study (i.e., copper, manganese, and vitamin A) did not change significantly throughout the menstrual cycle. Nonetheless, at "baseline" (the early follicular phase), even the trace mineral manganese was lacking, with 13% of women demonstrating a prevalence of low manganese status.
As mbg's vice president of scientific affairs, Ashley Jordan Ferira, Ph.D., RDN, explains: "Given that millions of American women of reproductive age fail to consume adequate amounts of these essential minerals day in and day out, the exacerbating trajectories of nutrients status demonstrated in this study are massive."
Ferira goes on to to share this important cautionary advice. "If we're not intentional about ensuring nutritional sufficiency each day, then the impact of inevitable nutrient fluctuations during our menstrual cycle throughout our life will be more weighty and have broad, negative health implications. They are called "essential" nutrients for a reason. They matter."