Vitamin Glossary "H"

• HDL cholesterol- a cholesterol-poor, protein-rich lipoprotein of blood plasma associated with a reduced risk of atherosclerosis.

   

• HDL-high density lipoproteins- a fat-transporting fraction of blood higher levels of which are believed to be associated with a reduced risk of heart disease.

   

• hemiplegia- paralysis of only one side of the body.

   

• hemoglobin- the iron-containing pigment of the red blood cells.

   

• hemolysis-bursting (lysis) of red blood cells. One way of measuring vitamin E deficiency is by finding out how easily the red blood cells burst when subjected to lysing agents such as hydrogen peroxide. Higher serum levels of vitamin E protect the red blood cells against hemolysis, unless they are then exposed to even higher concentrations of the oxidant hydrogen peroxide.

   

• hemorrhage- heavy or uncontrollable bleeding.

   

• hepatic- hepatics aid the liver by toning and strengthening it and in some cases increasing the flow of bile. They are fundamental in maintaining health because of the important role the liver plays by not only facilitating digestion but also removing toxins from the body.

   

• hepatoxic- any substance which is toxic to the liver.

   

• -5-HIAA-5-hydroxyindoleacetic acid- a breakdown product of the neurotransmitter serotonin.

   

• histamine- a substance produced by the body during an allergic reaction.

   

• histone- a basic protein associated with nucleic acids. Histones are important parts of the DNA control system, suppressing the expression of or causing the expression of specific parts of the DNA blueprints in conjunction with other nucleoproteins.

   

• hormone- a chemical messenger that is transported (often by the bloodstream) a relatively long distance from its source to the cells it affects. Insulin, vasopressin, testosterone, and cortisone are all examples.

   

• hydroperoxide-a type of organic peroxide.

   

• hydroxyl radicals- a particularly reactive, damaging type of free radical, formed when superoxide radicals react with hydrogen peroxide. Hydroxyl radicals are thought to be the principal damaging agent to joint membranes in arthritis. X-rays do most of their damage via hydroxyl radicals. Hydroxyl radicals can attack and damage any molecule in your body.

   

• hypothalamus- the master gland of neuroendocrine (hormone) control in the brain. It controls the pituitary's production and release of its own hormones. Appetite and body temperature control centers are located in the hypothalamus. It releases many hormones including LHRH, a natural aphrodisiac. An aging clock or clocks may be located in the hypothalamus.

   

• hypoxia- a condition of oxygen deficiency (but not total absence) in part or all of the body. Under conditions of hypoxia, free radical production is often greatly stimulated.