Non-anaemic Iron Deficiency clinical trials

Efficacy Evaluation of 16 Weeks' Dietary Supplementation With Iron Bis-glycinate Plus Vitamin C on Cognitive Function, Subjective Mood, Fatigue, Health and Well-being

Iron deficiency is the most prevalent nutritional deficiency worldwide with one in four estimated to be affected by iron deficiency anaemia. Women of reproductive age are at greatest risk for iron deficiency and anaemia due to iron losses during menstruation and childbirth as well as the increased need for iron throughout pregnancy. However, iron deficiency without anaemia is at least twice as common as iron deficiency anaemia with females aged 11-49 at the biggest risk of all. Despite this, it is commonly left undiagnosed. Those who are iron deficient non-anaemic can still suffer from the same common consequences of iron deficiency anaemia; these include unexplained fatigue, mood changes and decreased cognitive performance. However, randomised controlled trials (RCTs) assessing the effect of iron supplementation upon cognitive performance, mood, fatigue and well-being in non-anaemic iron deficient women of reproductive age are limited. There is also a lack of well-defined diagnostic criteria for non-anaemic iron deficiency, which makes comparisons across RCTs difficult. However, there is evidence to suggest that a haemoglobin cut off of ≥120 g/L and serum ferritin ≤ 20 µg/L provides an accurate indication of non-anaemic iron deficiency in women of reproductive age; this is inclusive of the ability to recognise iron-associated deficits in psychological and physiological functioning. Additionally, previous RCTs could be improved by utilising a lower dose of iron in a bis-glycinate chelate form, which is evidenced to have superior bioavailability, tolerability and subsequent efficacy compared to ferrous formulations. Iron bis-glycinate absorption is also negatively associated to serum ferritin levels, which is suggestive of a non-anaemic iron deficient population benefitting most from it's administration. The current study aims to build upon previous iron RCTs in populations of non-anaemic iron deficient and iron sufficient women of reproductive age by investigating the effects of 16-weeks supplementation with either iron bis-glycinate chelate alone, iron bis-glycinate plus vitamin C (as ascorbic acid) or matched placebo upon cognitive performance, subjective mood, fatigue, health and well-being.