Magnesium-B

[Nutrition Adviser Product Information]

The mineral magnesium

Magnesium acts as a structural, as well as functional, component in the body. This mineral is best known for its requirement in energy production as well as nerve and muscle function. It is interesting to note that the tissues with the highest magnesium concentration are also those which are metabolically most active, such as the brain, heart and liver. Sometimes magnesium is also referred to as the 'Anti-Stress Mineral'. It would appear that during times of stress magnesium is lost faster from the body whilst low magnesium body stores tend to predispose to stress, a vicious cycle.

Function

The mineral magnesium is the fourth most abundant cation in the body overall and the second most common mineral found intra-cellularly after potassium. The major holding store for magnesium in the body is bone, which comprises approximately 60% of the overall body content. The rest is found within the soft tissue cells, where it functions mainly to stabilise the structure of ATP (adenosine triphosphate) in ATP-dependent enzyme reactions. Approximately 300 metabolic enzyme reactions require magnesium including those involved in glycolysis and the Krebs cycle, essential for energy production. Others include various phosphatases and reactions in protein and nucleic acid synthesis. Magnesium (Mg2+) also plays a role either in opposition or in tandem with calcium in neuromuscular functions. (1,2)

Magnesium availability from the diet and absorption

Good food sources of magnesium include cereals and green leafy vegetables. (3) Wheat grains, which have had their husks removed as part of the refining process, may lose up to 80% of their magnesium content. (4) This may in part be responsible for the generally low magnesium content in the modern UK diet. Indeed government surveys, analysing an 'average' shopping basket for nutritional values, consistently indicate that the mineral magnesium may not be in adequate supply, according to official recommendations. (5)

Approximately 30-40 % of the dietary magnesium intake is believed to be absorbed, being inversely related to the amount present. Mg2+ is probably absorbed both by an active carrier mechanism and diffusion. (1) It would appear that even if sufficient levels of magnesium are obtained from the diet, many factors might affect optimal absorption. Inhibitory factors on magnesium absorption include phytates, a substance found in cereals and beans, a diet rich in saturated fats and/or low vitamin B6.

Factors that may interact with magnesium and thus influence its requirement include; calcium, protein, vitamin B6, vitamin B1 and vitamin D. Some studies indicate that high intakes of calcium may adversely affect magnesium retention in those who already have low magnesium intakes. The type of protein and the quantity of protein in relation to magnesium intake also has an effect on magnesium retention. Vitamins that depend on magnesium for their full expression include vitamin B6 and vitamin B1, both required for enzyme functions that also depend on magnesium. Some of these enzymes include phosophokinases, synthetases, phosphotases and enzymes involved in phosphate transfer from adenosine tri- and diphophate. Interestingly, just by increasing vitamin B6 intakes, intracellular magnesium levels have been raised. (6) Vitamin D is believed to be required for the absorption of magnesium and it would appear that the reverse is true, as the activation of vitamin D may well rely on a magnesium dependent enzyme.

Magnesium loss from the body may be accelerated with excess consumption of alcohol, coffee, tea, salt, phosphoric acid (soft drinks), sugar, diuretics and other medication. (7,8) Intense stress, sunlight as well as dehydration all increase magnesium excretion.

Low magnesium status and related conditions

A myriad of adverse health conditions may share low magnesium status as a contributing factor. These include fatigue, poor ability to adapt to stress, cardiovascular disorders, osteoporosis, sub-optimal immune function, painful periods and pre-menstrual headaches, problem pregnancies and migraines.

The various roles of magnesium in the body

Low energy/fatigue

As outlined already, a number of enzymes required for the production of the energy molecule (ATP) are magnesium dependent. Suboptimal energy supply can adversely affect a wide range of metabolic functions.

Bone health

Magnesium makes up 0.5-1% of bone ash and it would appear that magnesium influences both mineral and matrix metabolism of the bone by a combination of effects. These involve hormones as well as factors that regulate skeletal and mineral metabolism, and by direct effects on the bone itself. (10, 35) Diets providing good levels of potassium and magnesium have been shown to be associated with greater Bone Mineral Density at various sites. (11)

Nerve and muscle function

Magnesium is required to counterbalance the effect of calcium, which generally has a stimulating effect. Magnesium has been shown to reduce the electrical excitability of the neuron, blocking the release of acetylcholine from the nerve ending and blocking the effect of N-methyl-D-aspartate (NMDA), an excitatory neurotransmitter. (9)

Stress mechanism

When physical or mental demands are high, magnesium loss is accelerated. The adrenal glands, which play a key role in the body's ability to cope with stress, release adrenaline, an excitatory hormone. Magnesium is required as a co-factor for the metabolic pathway that produces adrenaline. (12) A suboptimal magnesium status has also been shown to cause the release of stress hormones, a process, which in turn depletes tissue magnesium levels. (36) These hormones stimulate the release of fatty acids, which when complexed with magnesium, reduce the bioavailability of this mineral. (13)

Cardiovascular system

Hypomagnesemia has been associated with atherosclerosis, hypertensive disorders, cerebral transient ischemic attacks and coronary spasm. (14) Hypertension may be exacerbated by a low magnesium and vitamin B6 status in those with high cholesterol, as these combined factors lead to diminished endothelial cell response to vasodilators and increased response to vasoconstrictors. (15) A healthy heart, as well as the smooth muscle function of the blood vessels, requires sufficient magnesium to be present. (16)

Magnesium may play an important role in regulating blood pressure. The Dietary Approaches to Stop Hypertension (DASH) study suggested that hypertension could be lowered by a diet high in magnesium, potassium and calcium and low in sodium and fat. (37) In the USA, the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure recommends maintaining an adequate magnesium intake for preventing and managing high blood pressure.

Muir states that Magnesium exhibits a range of neuronal and vascular actions that may ameliorate ischaemic CNS insults including stroke. (38)

Immune system

The release of nitric oxide (NO) from the cell may be adversely affected by a low magnesium status. NO is involved in a myriad of functions in the body, including a preventive role of infections involving the body cavities i.e. sinuses, throat or lungs. When NO production is limited bacteria have a favourable environment to thrive in. (17) An animal study indicates that during magnesium deficiency substances that can initiate inflammatory and immune responses may be increased. (18) Cytotoxicity may be enhanced when magnesium deficiency is present. (19)

Female hormonal balance

A study was conducted to investigate the effect of 200-mg magnesium oxide on pre-menstrual symptoms of fluid retention. In the second month of the study there was a greater reduction of symptoms of PMS-H in those taking the food supplement (weight gain, swelling of extremities, breast tenderness and abdominal bloating). (20) A different study has established a link between magnesium deficiency and adrenal hyperplasia, which may result in water retention. The role of magnesium in hormonal balance is further confirmed by its requirement for an enzyme involved in the hepatic glucuronidation of oestrogen. In addition the binding of oestrogen and progesterone to target tissue can be varied simply by increasing or decreasing magnesium. Glucose induced insulin output may be exacerbated when magnesium status is low, thus contributing to sweet cravings associated with PMS-C. Finally, the brain chemical dopamine may also be affected by a low magnesium status, which plays a part in counteracting anxiety. (21)

Essential fatty acid metabolism

The conversion of essential fatty acids into prostaglandins, hormone-like substances, is dependent on the availability of magnesium together with zinc and vitamins B3, B6 and C. Low supplies of any of the above mentioned nutrients may result in the symptoms of essential fatty acid deficiency, even if these are supplied in sufficient quantity in the diet. This may affect immunity and also cause abnormal sensitivity to prolactin often associated with the symptom of breast tenderness in PMS. (21, 22)

Problems during Pregnancy

Sufferers of pregnancy-induced high blood pressure and eclampsia have been shown to respond well to magnesium supplemention, with both groups experiencing favourable outcomes compared to the non-magnesium supplemented group. (23,24)

Migraine

Eighty-one patients received 600 mg of magnesium (trimagnesium dicitrate) for 12 weeks. Those taking the food supplement experienced in weeks 9-12 a 41.6 percent reduction in attack frequency, compared to 15.8 percent of the placebo group. The duration and intensity of the attacks, as well as drug consumption, also tended to decrease, but these factors failed to be significant. (25)

Diabetes

It has been found that magnesium deficiency can lead to impaired insulin secretion, and reduced insulin tissue sensitivity, in type 2 non-insulin-dependent diabetes mellitus. The correction of magnesium deficiency restores insulin secretion and sensitivity, even when no beneficial effects on glycemic control can be noted. In addition, it is likely that magnesium supplementation may help to support the cardiovascular system, which is often adversely affected as a result of the complications of diabetes. (39)

Vitamin B6

Vitamin B6 is the collective term for pyridoxine, the most common form of this vitamin found in plants, whilst pyridoxal and pyridoxamine phosphate is mostly found in animal tissue.

This vitamin acts as a coenzyme in more than 100 enzyme reactions, which includes amino acid synthesis and catabolism as well as their intestinal transport. Other functions include the formation of chemical transmitters in the nervous system, red blood cells and prostaglandins. Phospholipid synthesis and taurine production also require vitamin B6. (26,27)

The requirement for vitamin B6 is dependent on protein intake, which makes a deficiency more likely among those who have a high protein diet. (26) Other factors that may increase the requirement for this vitamin include certain food colourings (tartrazine), certain drugs, oral contraceptives and alcohol. Good food sources for this vitamin include whole grains, legumes, seeds and nuts. (27)

Conditions, which respond well to vitamin B6 supplementation, include pre-menstrual syndrome (PMS), carpal tunnel syndrome, depression and morning sickness. (27)

Vitamin B6 and magnesium enjoy a special relationship, as both nutrients require each other's presence for optimal function and absorption. Vitamin B6 deficiency has been found to intensify magnesium deficiency as both nutrients act as co-factors for a number of enzymes. It appears that some children with neurological disorders, who have been given high doses of vitamin B6, have subsequently developed magnesium deficiency and have been found to respond better to vitamin B6 therapy with added magnesium. (28) As already mentioned, one study showed that simply adding extra vitamin B6 as a daily food supplement could raise intracellular magnesium levels. (6)

Vitamin C

This vitamin is classed as a water phase antioxidant, which also regenerates vitamin E. Research studies indicate that vitamin C has an immune boosting effect in those who have low intakes of this vitamin. In addition, it is important for the synthesis of procollagen of connective tissue cells, especially during periods of growth. Strong connective tissues play a part in making the body more resistant to unwanted micro-organisms and increase the resilience of certain body tissues to wear and tear. An example is the pressure exerted on arteries by blood pressure. The adrenal medulla is one of the tissues with the highest vitamin C concentration, where this vitamin is involved in the production of hormones closely linked with stress control. (29, 30,31)

Vitamin-B complex

The B-complex vitamins play an important role in the metabolism of all cells and are particularly important in the processes involving energy production. It is believed the B-vitamins work best when a complete complex is present. (32)

Betaine hydrochloride

This substance is often used in supplement form to increase the acid content of the stomach to aid protein digestion. It is also believed that it helps with the absorption of certain minerals, vitamin C and protects B-vitamins. (33) A number of minerals require an acid environment for their optimum absorption. (34) A small amount has been added to Magnesium-B to aid the absorption of nutrients.

References:

1. Maria C. Linder (Ed.), Nutritional Biochemistry and Metabolism with Clinical Application- Second Edition, Prentice Hall International Inc., 1991

2. Michael F. Ryan, The role of magnesium in clinical biochemistry: an overview, Ann Clin Biochem, 1991, Vol 28, pp 19-26

3. Department of Health, Report on Health and Social Subjects, 41, Dietary Reference Values for Food Energy and Nutrients for the United Kingdom, HMSO, 1991, pp 146-49

4. R. Erdmann, M. Jones, Minerals the Metabolic Miracle Workers, Century Publishing, 1988, p 28

5. MAFF, National Statistics, National Food Survey 1999, Annual Report on Food Expenditure, Consumption and Nutrient Intakes, London: The Stationery Office, 2000

6. G. E. Abraham, Effects of vitamin B6 on plasma and red blood cell magnesium levels in premenopausal women, Ann Clin Lab Sci, 1981, Vol. 11, (4), pp 333-6

7. Mildred S. Seelig, Nutritional Status and Requirements for Magnesium, Mag.-Bull. 8, 1986, pp 170-185

8. S. Johnson, The multifaceted and widespread pathology of magnesium deficiency, Medical Hypotheses, 2001, Vol. 56, No. 2, pp 163-170

9. Richard A. Reinhart, Marshfield, Magnesium Metabolism, Wisconsin Medical Journal, October 1990, pp 579-583

10. S. Wallach, Effects of Magnesium on Skeletal Metabolism, Magnesium Trace Elem, 1990, Vol. 9, pp 1-14

11. K. Tucker et al., Potassium, magnesium, and fruit and vegetable intakes are associated with greater bone mineral density in elderly men and women, American Journal of Clinical Nutrition, 1999, Vol. 69, pp 727-36

12. R. Erdmann, M. Jones, Minerals the Metabolic Miracle Workers, Century Publishing, 1988, p 48

13. M. S. Seelig, Consequences of magnesium deficiency on the enhancement of stress reactions; preventive and therapeutic implications (a review), Journal of the American College of Nutrition, 1994, Vol. 13, (5), pp 429-46

14. D. P. Lauler, Introduction: Magnesium-Coming of Age, The American Journal of Cardiology, 1989, Vol. 63 (April 18), pp 1G-3G

15. S. Johnson, The multifaceted and widespread pathology of magnesium deficiency, Medical Hypotheses, 2001, Vol. 56, No. 2, pp 165

16. P. Wester, Magnesium and Hypertension, Journal of the American College of Nutrition, 1987, Vol. 6, (4), pp 321-328

17. S. Johnson, The multifaceted and widespread pathology of magnesium deficiency, Medical Hypotheses, 2001, Vol. 56, No. 2, pp 167

18. W. B. Weglicki et al., Immunoregulation by neuropeptides in magnesium deficiency: ex vivo effect of enhanced substance P production of circulating T lymphocytes from magnesium deficient mice, Magnesium Research, 1996, Vol. 9, (1) pp 3-11

19. T. Günther, Magnesium deficiency generally enhances cytotoxicity, Magnesium-Bulletin, 1990, Vol. 12, (2), pp 61-64

20. Ann F. Walker et al., Magnesium Supplementation Alleviates Premenstrual Symptoms of Fluid Retention, Journal of Women's Health, 1998, Vol. 7, (9), pp 1157-1165

21. P. Lewis, Helping PMS - naturally, International Journal of Alternative and Complimentary Medicine, 1996 (January), pp18 - 32

22. Udo Erasmus, Fats that Heal Fats that Kill, Alive Books, 1994, pp 51

23. Acta Obstet Gynaecol Scand, 1991, 70, (6), pp 445-50

24. Collaborative Eclampsia Trial, Lancet, 1995, Vol. 345, (8969), pp 1455-63

25. A. Peikert, C. Wilimzig, R. Köhne-Volland, Prophylaxis of migraine with oral magnesium: results from a prospective, multi-center, placebo-controlled and double-blind randomized study, Cephalalgia, 1996, Vol. 16, pp 257-63

26. Mildred S. Seelig, Nutritional Status and Requirements for Magnesium, Mag.-Bull. 8, 1986, pp 170-185

27. Michael T. Murray, Encyclopedia of Nutritional Supplements, Prima Publishing, 1996, pp 100-110

28. Mildred S. Seelig, Nutritional Status and Requirements for Magnesium, Mag.-Bull. 8, 1986, pp 170-185

29. Michael T. Murray, Encyclopedia of Nutritional Supplements, Prima Publishing, 1996, pp 59-79

30. Dr. S. Davies, Dr. A. Stewart, Nutritional Medicine, Pan Books, 1987, p 29

31. J. F. Balch, P. A. Balch, Prescription for Nutritional Healing - Second Edition, Avery Publishing Group, 1997, pp 18-19

32. Maria C. Linder (Ed.), Nutritional Biochemistry and Metabolism with Clinical Application- Second Edition, Prentice Hall International Inc., 1991

33. R. Greer, R. Woodward, The Good Nutrients Guide, J. M. Dent & Sons Ltd., 1985, pp 170-171

34. R. Erdmann, M. Jones, Minerals the Metabolic Miracle Workers, Century Publishing, 1988, p 142

35. G. E. Abraham, The Calcium Controversy, Journal of Applied Nutrition, 1982, Vol. 34, (2), pp 69-73

36. Y. Itokawa, J. Durlach, (Eds.), Magnesium in Health and Disease, John Libbey & Co. Ltd., 1989, pp 271-278

37. Appel et al, 1997, New Eng J Med 336: 1117-1124

38. Muir K. W., Magnesium for neuroprotection in ischaemic stroke: rationale for use and evidence of effectiveness, CNS Drugs, (New Zealand), 2001, 15 (12), pp 921-30

39. Iannello S., Belfiore F., Hypomagnesemia, a review of pathophysiological, clinical and therapeutical aspects, Panminerva Med, 2001, Vol 43, pp 198-9