From the Guidelines
Treating magnesium and calcium deficiencies in colitis patients requires both oral and sometimes intravenous supplementation, prioritizing the most recent and highest quality evidence available 1. For magnesium deficiency, start with oral magnesium oxide 400-800 mg daily or magnesium citrate 200-400 mg daily in divided doses, as recommended in recent studies 1. If oral supplements aren't tolerated or levels are severely low, consider IV magnesium sulfate 1-2 g over 1-2 hours, taking into account the potential for gastrointestinal intolerance and other side effects 1. For calcium deficiency, prescribe calcium carbonate 1000-1500 mg elemental calcium daily in divided doses with meals, or calcium citrate 800-1200 mg daily if the patient has low stomach acid, ensuring adequate vitamin D supplementation (1000-2000 IU daily) for optimal calcium absorption 1. Monitor serum levels every 1-2 weeks initially, then monthly once stabilized, and treat the underlying colitis simultaneously, as inflammation reduces nutrient absorption 1. Patients should be advised that magnesium supplements may worsen diarrhea, while calcium supplements might cause constipation, requiring dose adjustments, and long-term management should include a diet rich in these minerals once the acute colitis improves, focusing on leafy greens, nuts, dairy or fortified alternatives, and limiting foods that may interfere with absorption like high-oxalate foods or excessive caffeine 1. Key considerations include:
- Starting with lower doses of magnesium and gradually increasing as tolerated to minimize side effects 1
- Choosing the appropriate form of calcium supplement based on the patient's stomach acid levels 1
- Ensuring adequate vitamin D supplementation for calcium absorption 1
- Monitoring for potential interactions with other medications or foods that may affect absorption 1
From the FDA Drug Label
In the treatment of mild magnesium deficiency, the usual adult dose is 1 g, equivalent to 8. 12 mEq of magnesium (2 mL of the 50% solution) injected IM every six hours for four doses (equivalent to a total of 32.5 mEq of magnesium per 24 hours). For severe hypomagnesemia, as much as 250 mg (approximately 2 mEq) per kg of body weight (0. 5 mL of the 50% solution) may be given IM within a period of four hours if necessary. Alternatively, 5 g (approximately 40 mEq) can be added to one liter of 5% Dextrose Injection, USP or 0. 9% Sodium Chloride Injection, USP for slow IV infusion over a three-hour period.
Treatment of Magnesium Deficiency:
- For mild magnesium deficiency, administer 1 g (8.12 mEq) of magnesium IV or IM every 6 hours for 4 doses.
- For severe hypomagnesemia, administer 250 mg (2 mEq) per kg of body weight IV or IM within 4 hours if necessary.
- Alternatively, administer 5 g (40 mEq) of magnesium in 1 liter of 5% Dextrose Injection or 0.9% Sodium Chloride Injection for slow IV infusion over 3 hours.
Warnings to Patient:
- Monitor serum magnesium levels to avoid exceeding renal excretory capacity.
- Be cautious of potential incompatibilities with other medications.
- Inform patient of potential side effects and monitor for signs of magnesium toxicity.
From the Research
Treatment of Magnesium and Calcium Deficiencies
To treat magnesium and calcium deficiencies in a patient with colitis, the following steps can be taken:
- Monitor serum magnesium and calcium levels, as well as urinary excretion of magnesium, to assess the severity of the deficiencies 3
- Provide parenteral magnesium supplementation of at least 120 mg/day, or more depending on fecal or stomal losses, to patients with severe deficiencies 3
- Recommend oral magnesium supplementation of up to 700 mg/day, depending on the severity of malabsorption, to patients with mild to moderate deficiencies 3
- Ensure adequate dietary intake of calcium and magnesium through a balanced diet or supplements, as inadequate intake can exacerbate deficiencies 4, 5
- Consider prophylactic oral administration of magnesium to ameliorate colitis symptoms, as it has been shown to decrease colonic accumulation of P2X7 receptor-expressing mast cells 6
Warnings to Patient
The patient should be warned about the potential complications of magnesium and calcium deficiencies, including:
- Cramps, bone pain, delirium, and cardiac abnormalities due to magnesium deficiency 3
- Osteoporosis and increased risk of fractures due to calcium deficiency 5
- Importance of regular monitoring of serum magnesium and calcium levels, as well as urinary excretion of magnesium, to adjust supplementation doses as needed 3
- Potential interactions between magnesium and calcium supplements and other medications, such as sulfasalazine and corticosteroids, which can affect their absorption and efficacy 7