A recent study published in the journal, Nutrients, evaluated the relationship between vitamin D and iron deficiency in elite female athletes.
Serum blood samples were drawn from 219 professional female athletes. The women represented seven different sports, including volleyball, handball, rowing, canoe sprint, cycling, speed skating and taekwondo. Approximately 51% of the participants had their blood drawn during the months of April-September, while the remaining 49% were tested between October and March.
The researchers did not interview the athletes regarding their vitamin D and/or iron intake, however, participants were excluded if they displayed lab values that could be related to abnormal vitamin D or iron status. This included abnormal white blood cell counts and high C-reactive protein, common markers of inflammation.
This is what the researchers found:
- Approximately 54% of the participants had vitamin D levels below 30 ng/ml (75 nmol/l).
- Approximately 23% of the participants experienced total iron deficiency.
- Those who were iron deficient had a nearly 3 times increased odds of also being vitamin D deficient (p = 0.003).
- This association was also true in reverse. Those who were vitamin D deficient had a 2.73 times increased odds of being iron deficient (p = 0.007).
The researchers concluded:
“The current results clearly indicate an association between both analyzed nutrients. However, due to the observational study design, it is difficult to assess exactly which of these nutrients exerts a stronger influence on the other.”