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Quest Vitamins LTD,
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Endocrine System


Communication between the cells, tissues and organs that collectively compose our body is fundamental to growth and development, and the maintenance of the body’s internal environment. Interaction occurs between the nervous and endocrine systems, which co-ordinate the various functions of all body systems. The latter is concerned with regulating activities that require duration rather than speed.


The endocrine system is composed of glands that secrete blood-borne messenger molecules called hormones. These hormones then circulate around the body until they find a cell that has a receptor which they can bind to and exert their effect. In addition, several glands contain cells that secrete hormones - examples include(4):

Hypothalamus - connects with the pituitary gland and co-ordinates functions of nervous and endocrine systems
Pancreas - secretes insulin and glucagon for controlling the body's utilisation of glucose
Ovaries - produce the hormones oestrogen and progesterone, controlled by gonadotrophic hormones secreted by the pituitary
Testes - produce testosterone, controlled by gonadotrophins secreted by the pituitary. These hormones stimulate sperm production and the development of other male characteristics
Parathyroid - secrete parathyroid hormone which maintains the Calcium level in blood
Thyroid - produces thyroxine (metbolism), triiodothronine (body heat) and calcitonin (bone growth). Thyroid activity controlled by Thyroid Secreting Hormone (TSH), secreted by the pituitary
Pituitary - secretes hormonesthat stimulate the adrenals, thyroid pigment-producing cells, and gonads; also growth hormone, antidiuretic hormone, prolactin, and oxytocin
Adrenal Cortex - adrenocorticotropic hormone (ACTH) stimulates the adrenal cortex into producing hydrocortisone; it also produces anrogen hormones and aldosterone which maintains blood pressure and salt balance in the body

Hormones have very powerful effects even when present at very low concentrations. Nonetheless, they are very specific, and only act upon a few cell types.

Function of hormones

Hormone functions can be broadly divided into seven broad areas:

1. Regulate the chemical composition of the fluid that bathes all of our body cells and tissues
2. Help to regulate general metabolism and energy balance
3. Assist in the regulation of cardiac and smooth muscle contraction
4. Keep the body in balance in spite of disruptions such as Infection, trauma, emotional Stress, dehydration, starvation, haemorrhage and temperature extremes
5. Modulate various facets of the Immune System
6. Play a role in reproduction
7. Support growth and development

The powerful effect of hormones on various body structures and functions is illustrated no better than during puberty. During this stage of development, changes in the brain and the pituitary gland lead to an increase in the production of hormones. In girls, fatty tissue is deposited in the breasts and around the hips whereas in boys, protein synthesis increases, muscle mass builds, and longer, larger vocal cords produce a lower-pitched voice.


In all endocrine disorders there is either insufficient or excessive production of a hormone by a gland. There are a number of reasons why this may occur and common causes include tumour, an autoimmune disease of the gland or a disorder of the hypothalamus or pituitary gland.

An abnormal decrease in blood sugar concentrations, hypoglycaemia exists in two forms: fasting and reactive. Fasting hypoglycaemia occurs after a long period without food (such as before breakfast), and is characterised by a dangerously low blood glucose level during the fasting state. In reactive hypoglycaemia, blood glucose levels drop immediately following a meal. Symptoms of hypoglycaemia include tiredness, dizziness, hunger pangs, heart palpitations and excessive sweating (4).

Those with hypoglycaemia should base their diet around foods high in complex carbohydrates and avoid foods containing high levels of sugar. In addition, four to six small meals a day should be consumed rather than three large meals, thus helping to maintain a constant blood sugar level. From a supplemental point of view, many nutritionally-orientated doctors advise sufferers to take supplements providing 200ug of Chromium. Chromium is a trace Elements involved in glucose tolerance and has been shown in clinical studies to normalise blood glucose levels (1). Supplementing the diet with additional Zinc (15mg), Manganese (15mg) and Vitamin C (2000mg) may also be useful.

Adrenal Disorders
The adrenal gland produces the hormone adrenaline, which is required to create the "fight or flight" response and enables the body to cope with emergency situations. However, in certain conditions this gland may become overactive, resulting in a condition called Cushing’s Syndrome. In much rarer cases, insufficient adrenaline may be produced resulting in the condition Addison’s disease (4).

Supplements which support the health of the adrenal glands include Pantothenic Acid (vitamin B5), Liquorice, Siberian Ginseng and the amino acid L-tyrosine (2).

Thyroid Disorders
The thyroid gland is a bow tie shaped gland located just below the voice box and is responsible for producing the hormone thyroxine, which determines the body’s overall metabolic rate. The basic ingredients required to synthesise this hormone are L-tyrosine and Iodine.

Thyroxine affects virtually every body system, especially heart function and the development of the nervous system. Abnormally low levels of this hormone (hypothyroidism) stunts growth in children, but is usually reversible with thyroid replacement therapy. However, if an individual has hypothyroidism from birth, then this expresses itself as dwarfism and severe mental retardation, often referred to as cretinism.

In adults the symptoms are less serious, but still have a serious impact on the health of the individual. Sufferers experience Fatigue, weight gain, poor concentration, increased sensitivity to cold temperatures and puffiness to the face, hands and feet. Treatment for hypothyroidism usually involves the administration of thyroid hormone, except where the cause is inadequate dietary iodine. In these cases, patients may be given prescribed Iodine supplements. However, iodine in the form of Kelp may be taken to stimulate a slightly under-active thyroid gland that does not warrant medical treatment (3).

An excessive production of the hormone thyroxine increases the metabolic rate which results in various physical symptoms, namely excessive sweating, poor tolerance of heat, weight loss and heart palpitations. Treatment usually involves the surgical removal of a portion of the thyroid gland, administration of radioactive iodine, or the use of anti-thyroid drugs.


The "change of life" is a period of a woman’s life when keeping hormone levels balanced is vital to a healthy Menopause. The menopause usually takes place between the ages of 45 and 55 years - a time during which the ovaries stop releasing ova and periods gradually cease to occur. It is the changing and sometimes erratic hormone imbalances (particularly lowered oestrogen levels) that are responsible for the problems that many women experience during the menopause (4).

The symptoms of the menopause vary enormously between individuals, including Hot Flushes, vaginal dryness, poor concentration, panic attacks, mood swings, weight gain and increased risk of Osteoporosis. In the past Hormone Replacement Therapy (HRT) was the only available treatment for menopausal symptoms. However, this is no longer the case.

Many women are unhappy with the side effects of HRT and choose a more natural, long term approach to managing their symptoms. Taking a good quality multivitamin and mineral each day will go some way to safeguard against any nutritional inadequacies in the diet during this stage in life.

Approximately 70% of menopausal women are troubled by Hot Flushes (or night sweats) which may vary considerably in frequency and severity over a period of a few years. Vitamin E has been found to help reduce hot flushes, typical intakes daily between 400-600i.u. daily. Studies have also found Vitamin E to be useful for vaginal dryness (5).

Agnus Castus (Vitex agnus castus) is a herb taken by many women to help maintain a healthy hormone balance and therefore naturally manage menopausal symptoms without the use of synthetic hormones (6). Also, St John’s wort (Hypericum perforatum) has been shown to improve symptoms such as Depression and Anxiety (8). Suggested intake for those with emotional disturbances during the Menopause are 300-1000mg standardised herb extract daily.

Low oestrogen levels during and after the menopause reduces the body’s ability to absorb Calcium and therefore increase the risk of Osteoporosis (brittle bone disease). By increasing the dietary intake of Calcium and Vitamin D (together with regular weight-bearing exercise) bone density can be maintained into old age. The latest research from the National Osteoporosis Society suggests long term Calcium intakes of 1500mg for those aged 45 years and over and 1000mg for those taking HRT.

Menopausal women are advised to drink plenty of water and consume a diet of fresh fruit and vegetables. Also, fatty foods and sugar should be avoided as far as possible. Increased intakes of phyto-(plant) oestrogen may help to balance hormone levels during the menopause (8). Foods to be encouraged include soya (soya drinks, tempeh, tofu etc), flaxseed, nuts, whole grains, Alfalfa and Parsley.


Agnus Castus
Siberian Ginseng
St. John's Wort


Vitamin B5
Vitamin C
Vitamin D
Vitamin E
Multinutrient supplement vitamin & mineral


1. Regul Toxicol Pharmacol, 1997, 26;1 Pt 2:S35-41.
2. Biochem-Biophys-Res-Commun, 1990, 171(3), 1199-1204.
3. J Clin Endocrinol Metab, 1994, 78;393-397.
4. The BMA Complete Family Health Encyclopedia, Ed. Dr T Smith. 1995.
5. Healing Through Nutrition, M Werbach, Thorsons, 1995.
6. Woman Medicine "Vitex Agnus Castus" Simon Mills, 1992.
7. Arzeimittelforschung, 1984, 34:918
8. Overcoming the Menopause Naturally, Dr CM Shreeve, 1987.