Calcium and vitamin D substitution has for a long time been used to improve osteoporosis.The main storage place for magnesium is in the bone. Magnesium is direct under calcium in the periodic system making it possible to interact with the crystal structure. Some small studies have shown beneficial effects of magnesium substitution on osteoporosis. Evidence has shown improvement with calcium, alcohol, fruit and vegetable nutrients on bone loss. It has been uncertain however, which of these factors can contribute to such a change. The effect of magnesium substitution 240 mg daily as therefore studied in two parallel groups where both received calcium carbonate 1000 mg/day and cholecalciferol 10 ug/day, one got placebo and the other received magnesium. This was studied on various expressions for bone metabolism after zero, seven and 28 days in elderly females aged 70 years old.

Elderly 70 year old ladies who had been to an outpatient X-ray investigation were invited to participate in this study. They were all healthy without any signs of osteoporosis, or fractures.They were stimulated to participate by having done bone density measurements free. Patients who had used biphosphonates, oestrogens, glucocorticoids , diuretics, immunomodulating agents, or prolonged use of heparin were excluded.

Patients with possible secondary osteoporosis due to primary hyperthyroidism or chronic lung disease were also excluded. The participants were randomized into placebo or Mg-treatment groups. They were seen by the dietician, and blood and urine samples were taken at day 0, 7 and 28 at the same time these days. Medicine was prepacked for intake twice daily. They received medicine for 30 days and should only take for 28 days. The number of tablets which should be left was controlled the last day. The participants were informed about the results of the bone density measurements taken the first and the last day. All the patient contacts were undertaken by the same dietician.

Inclusion Criteria:

Homeliving healthy female volunteers aged 70 years old were recruited by phone.

Exclusion Criteria:

Persons who had used:

• biphosphonates,

• oestrogens,

• glucocortocoids,

• antiepileptic drugs,

• diuretics,

• immunmodulating agents,

• prolonged usage of heparin.

• patients with possible secondary osteoporosis and

• diagnosis as:

  • inflammatory bowel disease,
  • primary hyperthyroidisms,
  • chronic obstructive lung disease