Calcium beta-hydroxy-beta-methylbutyrate
Encyclopedia
Calcium β-hydroxy-β-methylbutyrate or calcium HMB is a nutritional supplement, which represents a calcium salt of beta-hydroxy beta-methylbutyrate
(HMB). The latter is a leucine
metabolite produced in the body through oxidation of the ketoacid of leucine (ketoisocaproate, KIC
). Because leucine plays an important regulatory role in protein metabolism and due to the conversion of leucine to KIC, several researchers have presumed that KIC was the active ingredient responsible for most of the beneficial effects of leucine on protein metabolism. In addition to its effects on protein metabolism, some studies demonstrated a major role for added leucine and leucine metabolites (HMB, β-hydroxy butyrate BHB, β-hydroxy methyl glutarate HMG) in modulating the immunocompetence cells, especially of lymphocyte
activity. According to the results, the only direct leucine metabolite to affect lymphocyte blastogenesis was HMB.
(13% to 15%), and water from 5.0% to 7.5%. It may contain trace amounts of heavy metals such as lead
NMT 1 ppm and arsenic
NMT 1 ppm.
, promote fat loss, increase strength and fat-free mass in athletic and nonathletic populations. However, it is less clear whether HMB supplementation promotes these adaptations in trained athletes. A study made by several scientists examined the effects of HMB (as the calcium salt) supplementation during resistance training (6.9±0.7 hr × wk(-1)) on markers of catabolism, body composition and strength in experienced resistance-trained males. In a randomized manner, 40 experienced resistance-trained athletes were matched and assigned to supplement their diet for 28 days with a fortified carbohydrate
/protein powder containing either 0, 3 or 6 g × d(-1) of calcium HMB. Fasting venous blood and urine samples, dual energy X-ray
absorptiometer-determined body composition, and isotonic bench press and leg press one repetition maximums (1 RM) were determined prior to and following 28 days of supplementation. The result of HMB supplementation was significant increases in serum
and urinary HMB concentrations. However, the study demonstrated no statistically significant differences in general markers of whole body anabolic/catabolic status, muscle and liver enzyme efflux, fat/bone-free mass, fat mass, percent body fat, or 1 RM strength. Results indicate that 28 days of the use of HMB supplementation during resistance-training does not significantly reduce catabolism or affect training-induced changes in body composition and strength in resistance-trained males.
As to other possible benefits of calcium HMB, the supplement is proved to be an efficient phosphate
binder in vitro, which may predict its effective role in vivo to treat such conditions as uremia
.
Beta-hydroxy beta-methylbutyrate
β-Hydroxy β-methylbutyric acid , or β-hydroxy β-methylbutyrate, is a metabolite of the essential amino acid leucine and is synthesized in the human body. It plays a part in protein synthesis and was discovered by Dr. Steven L. Nissen at Iowa State University. It has been used in scientific studies...
(HMB). The latter is a leucine
Leucine
Leucine is a branched-chain α-amino acid with the chemical formula HO2CCHCH2CH2. Leucine is classified as a hydrophobic amino acid due to its aliphatic isobutyl side chain. It is encoded by six codons and is a major component of the subunits in ferritin, astacin and other 'buffer' proteins...
metabolite produced in the body through oxidation of the ketoacid of leucine (ketoisocaproate, KIC
KIC
KIC may represent:* The IATA airport code for Mesa Del Rey Airport* The ICAO airline code for Kiwi Travel International Airlines* The ISO 639-3 language code for Kickapoo, see ISO 639:kic* Kepler Input Catalog of stars...
). Because leucine plays an important regulatory role in protein metabolism and due to the conversion of leucine to KIC, several researchers have presumed that KIC was the active ingredient responsible for most of the beneficial effects of leucine on protein metabolism. In addition to its effects on protein metabolism, some studies demonstrated a major role for added leucine and leucine metabolites (HMB, β-hydroxy butyrate BHB, β-hydroxy methyl glutarate HMG) in modulating the immunocompetence cells, especially of lymphocyte
Lymphocyte
A lymphocyte is a type of white blood cell in the vertebrate immune system.Under the microscope, lymphocytes can be divided into large lymphocytes and small lymphocytes. Large granular lymphocytes include natural killer cells...
activity. According to the results, the only direct leucine metabolite to affect lymphocyte blastogenesis was HMB.
Physical and chemical properties
Calcium HMB is a white powder, freely soluble up to 25%. Normally, the compound contains beta-hydroxy beta-methylbutyric acid (77% to 82%), calciumCalcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
(13% to 15%), and water from 5.0% to 7.5%. It may contain trace amounts of heavy metals such as lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
NMT 1 ppm and arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
NMT 1 ppm.
Uses
Calcium beta-hydroxy beta-methylbutyrate, as a dietary supplement, may affect protein synthesis. During resistance training, calcium beta-HMB has been reported to reduce muscle catabolismCatabolism
Catabolism is the set of metabolic pathways that break down molecules into smaller units and release energy. In catabolism, large molecules such as polysaccharides, lipids, nucleic acids and proteins are broken down into smaller units such as monosaccharides, fatty acids, nucleotides, and amino...
, promote fat loss, increase strength and fat-free mass in athletic and nonathletic populations. However, it is less clear whether HMB supplementation promotes these adaptations in trained athletes. A study made by several scientists examined the effects of HMB (as the calcium salt) supplementation during resistance training (6.9±0.7 hr × wk(-1)) on markers of catabolism, body composition and strength in experienced resistance-trained males. In a randomized manner, 40 experienced resistance-trained athletes were matched and assigned to supplement their diet for 28 days with a fortified carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...
/protein powder containing either 0, 3 or 6 g × d(-1) of calcium HMB. Fasting venous blood and urine samples, dual energy X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
absorptiometer-determined body composition, and isotonic bench press and leg press one repetition maximums (1 RM) were determined prior to and following 28 days of supplementation. The result of HMB supplementation was significant increases in serum
Serum
Serum may refer to:*Blood serum, a component of blood which is collected after coagulation.**Antiserum, blood serum with specific antibodies for passive immunity*Serous fluid, any clear bodily fluid*any drug derived from an animal's blood or serous fluid...
and urinary HMB concentrations. However, the study demonstrated no statistically significant differences in general markers of whole body anabolic/catabolic status, muscle and liver enzyme efflux, fat/bone-free mass, fat mass, percent body fat, or 1 RM strength. Results indicate that 28 days of the use of HMB supplementation during resistance-training does not significantly reduce catabolism or affect training-induced changes in body composition and strength in resistance-trained males.
As to other possible benefits of calcium HMB, the supplement is proved to be an efficient phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
binder in vitro, which may predict its effective role in vivo to treat such conditions as uremia
Uremia
Uremia or uraemia is a term used to loosely describe the illness accompanying kidney failure , in particular the nitrogenous waste products associated with the failure of this organ....
.