The Effects of Supplementary Cr3 (Chromium(III) Propionate Complex) on the Mineral Status in Healthy Female Rats
The Effects of Supplementary Cr3 (Chromium(III) Propionate Complex) on the Mineral Status in Healthy Female Rats
Halina Staniek 0
Zbigniew Krejpcio 0
0 Department of Human Nutrition and Hygiene, Poznań University of Life Sciences , ul. Wojska Polskiego 31, 60-624 Poznań , Poland
More and more people use food supplements for various reasons, e.g. to prevent mineral deficiency and diseases (e.g. osteoporosis, diabetes, anaemia). Supplements containing Cr(III) are purchased primarily for weight loss and antidiabetic effects. The aim of this study was to evaluate the effects of supplementary Cr3 {chromium(III) propionate complex, [Cr3O(O2CCH2CH3)6(H2O)3]NO3)} on the mineral status in female Wistar rats. The study was carried out on 30 female Wistar rats, divided into five groups (six animals in each): a control group and test groups fed Cr3 supplemented diets with 100, 200, 500 and 1000 mg Cr · kg−1 diet (equivalent to 10, 20, 50 and 100 mg Cr ·kg−1 body mass (b.m.) per day) given as Cr3 for 4 weeks. Supplementary Cr3 increased the Cr content in tissues in a dose-dependent manner. High dietary doses of Cr3, 20 and 100 mg Cr · kg−1 b.m., increased the Cu content in the liver and spleen as well as the Zn content in the kidneys but decreased the liver Ca content. Doses of 50100 mg Cr ·kg−1 b.m. decreased the serum Fe concentration and the Fe content in the liver and kidneys. Supplementation with Cr3 at doses of 10 and 100 mg Cr ·kg−1 b.m. did not affect the Mg content in the rats' tissues. In conclusion, high dietary doses of Cr3 (10 and 100 mg Cr· kg−1 b.m.) given for 4 weeks affected the mineral status of Fe, Zn, Cu and Ca in the tissues of healthy female Wistar rats.
Chromium(III) propionate; Rats; Mineral status
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In recent years, chromium has been one of the most
investigated dietary minerals. Chromium is a trace mineral that has
received much attention as a dietary supplement because good
dietary sources of chromium are scarce and the intake is
usually low. Chromium(III) deficiency may contribute to
carbohydrate metabolism disorder [1].
Many trials proved the positive effect of supplementary
chromium(III) on fasting plasma glucose, lipid variables,
especially in diabetic subjects [2–4]. For this reason, trivalent
chromium has been postulated to be necessary for insulin efficacy in
regulating the metabolism of carbohydrates, lipids and protein
[5]. A number of chromium compounds can be considered as a
perspective for metabolic syndrome treatment [6].
For over 50 years, chromium has generally been believed
to be an essential trace element. However, the mechanism(s)
of Cr action at the molecular level for this role and its
essentiality have not been substantiated. Recent research has not
supported the role of chromium [7].
In 2002, the Food and Nutrition Board of the US National
Academy of Science set the Adequate Intake (AI) of
chromium at 25 μg ·day−1 for adult women and 35 μg ·day−1 for men
[8], which was lower than the previous recommended dietary
intake of 50–200 μg per day. Recently, the EFSA panel found
no evidence of beneficial effects associated with chromium
intake in healthy subjects and concluded that setting the AI
for chromium was not appropriate [5].
In general, the oral intake of chromium has low toxicity
partially due to its poor absorption (about 0.5–2.0%).
However, different Cr(III) compounds have diverse rates
of absorption [9]. Organic Cr(III) forms have greater
bioavailability than inorganic ones. It is well known that the
mineral intake at high doses has antagonistic effects on
other elements [9].
Chromium is one of the best-selling mineral supplements
in the USA [10]. Trivalent chromium, the form found in food
and dietary supplements, is considered to be safe. Many
organic chromium complexes, including chromium picolinate
[Cr(Pic)3], chromium nicotinate (NCB) [11, 12], chromium
histidinate (CrHis) [13, 14], chromium complex of
D-phenylalanine [Cr(D-Phe)3] [15, 16], chromium propionate complex
(Cr3) [4, 17–19] and chromium glycinate complex (CrGly)
[19], have been synthesised and demonstrated to be
biologically effective. Different coordinate ligands of these organic
chromium complexes exhibited different bioactive
compounds [20].
For humans, a typical Cr intake is 20–45 μg per day in
the diet [21], while doses of supplements may contain
200–1000 μg Cr(III) [1, 22]. These doses correspond to
d a i l y b o d y w e i g h t - a d j u s t e d d o s e s o f 0 . 2 9 –
0.64 μg Cr(III)· kg−1 body mass (in the diet) and 2.86–
14.3 μg Cr(III) ·kg−1 b.m. (in supplements) in an
individual with an average weight of 70 kg [23].
Few studies have been designed to evaluate the effects of
trivalent Cr supplementation on the content of Cr and other
minerals in animal tissues. Chromium is distributed to various
tissues of the body but appears to be most concentrated in the
kidneys, liver and muscles [24]. Dietary Cr supplementation
at high doses can potentially affect the mineral status due to (...truncated)