VDC test kit slider

Vitamin D deficiency in relation to iron deficiency: is there a link?

Posted on: February 14, 2018   by  Vitamin D Council


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.”


Malczewska-Lenczowska, J. et al.The Association between Iron and Vitamin D Status in Female Elite Athletes. Nutrients, 2018.


4 Responses to Vitamin D deficiency in relation to iron deficiency: is there a link?

  1. [email protected]

    Over 20 studies have found an association between Low Iron and Low Vitamin D
    Level of both iron and Vitamin D have been decreasing in recent decades
    Several intervention studies have found that increasing one increases the other

  2. [email protected]

    A relationship between iron and vitamin D has been seen in one study I know and it was in very narrow conditions which concerned patients in critical care. The patients in the placebo group and the vitamin D group were anaemic. The vitamin D group was given 500,000 IU of D3 over 5 days. In the first week, the D3 group had an improvement in hemoglobin and a reduction in hepcidin. The hepcidin had been blocking the iron in macrophages which caused the anemia. When the hepcidin level decreased, the iron barrier was removed and iron became available.at least to a clinically meaningful extent. Another vitamin D group was given 250,000 IU of D3 over 5 days and there was no change in hepcidin nor hemoglobin. The increase in hemoglobin seen in the higher dose group may mean that very high dose vitamin D could be used to substitute for blood transfusions in critical care.
    In addition, I found the following in Wikipedia: Vitamin D has been shown to decrease hepcidin, in cell models looking at transcription and when given in big doses to human volunteers. Optimal function of hepcidin may be predicated upon the adequate presence of vitamin D in the blood.

  3. [email protected]

    500,000 IU was the total D3 over 5 days at 100,000 IU per day. 250,000 IU was also a total.

  4. TheSouthIsHot

    I get very uncomfortable side effects when I take D3 or D2: my quads ache and tingle and feel tight and my legs feel weak all over. I’ve tried taking D3 with magnesium, K2, and a few other cofactors that I can’t think of at the moment. I always get those side effects. HOWEVER, about 6 months ago, I began taking an iron supplement and then, about 2 months ago, I tried the D3 again and discovered that the side effects are greatly diminished when I take the iron and the D3 together. I’m very happy because my brain works better when I take D3.

Test Your Vitamin D Levels at Home!

Our in-home vitamin D test kit is easy, affordable, and an accurate way to find out your Vitamin D status.

order NOW

We need your help!

We're spreading awareness on Vitamin D Deficiency
Donate NOW
Latest Articles
What is the relationship between vitamin D and childhood UTIs?

A new study suggests vitamin D may protect against UTIs among children by upregulating their own naturally occurring antimicrobial peptides.

Weekly Newsletter

Our Sponsors

December 21st is DDAY. Click here to celebrate the day with us!