| Acktiva Supplement Facts
Serving Size: 2 Capsules
Servings Per Container: 30
Vitamin D (Cholecalciferol)
| Yielding Magnesium
Other Ingredients: Gelatin, Rice Powder, Magnesium Stearate.
*Daily Value Not Established
Daily Dosage: As a dietary supplement, take one capsule in the morning and one capsule in the evening with 8 ounces of water. 45-60 days of continuous use is necessary for optimum results.
Possible Interactions with: Vitamin D
If you are currently being treated with any of the following medications, you should not use vitamin D supplements without first talking to your healthcare provider.
Vitamin D levels may be increased by the following medications:
- Estrogen: Hormone replacement therapy with estrogen appears to increase vitamin D levels in the blood; this may have a beneficial effect on calcium and bone metabolism. In addition, use of vitamin D supplements in conjunction with estrogen replacement therapy (ERT) increases bone mass more than ERT alone. However, this benefit may be lost with the addition of progesterone.
- Isoniazid (INH): INH, a medication used to treat tuberculosis, may raise blood levels of vitamin D.
- Thiazide: Diuretics in this class (such as hydrochlorothiazide) increase the activity of vitamin D and can lead to inappropriately high calcium levels in the blood.
Vitamin D levels may be decreased, or its absorption may be reduced, by the following medications:
- Antacids: Taking certain antacids for long periods of time may alter the levels, metabolism, and availability of vitamin D.
- Calcium-channel blockers (such as verapamil): These medications are used to treat high blood pressure and heart conditions may decrease the production of vitamin D by the body.
- Cholestyramine: This cholesterol-lowering medication, known as a bile acid sequestrant, interferes with the absorption of vitamin D (as well as other fat soluble vitamins).
- Phenobarbital, phenytoin, and other anticonvulsant medications: These medications may accelerate the body's use of vitamin D.
- Mineral oil also interferes with absorption.
In addition, Vitamin D may enhance the effects of doxorubicin, a medicine used to treat a variety of cancers. More research is needed.
Some clinicians recommend following calcium levels closely if vitamin D is taken with digoxin, a medication used to treat irregular heart rhythms. This is because vitamin D improves absorption of calcium. Calcium, in turn, can increase the likelihood of a toxic reaction from this medication.
Weight Loss Products
Orlistat, a medication used for weight loss and olestra, a substance added to certain food products, are both intended to bind to fat and prevent the absorption of fat and the associated calories. Because of their effects on fat, orlistat and olestra may also prevent the absorption of fat-soluble vitamins such as vitamin D. Given this concern and possibility, the Food and Drug Administration (FDA) now requires that vitamin D and other fat soluble vitamins (namely, A, E, and K) be added to food products containing olestra. How well vitamin D from such food products is absorbed and used by the body is not clear. In addition, physicians who prescribe orlistat add a multivitamin with fat soluble vitamins to the regimen.
Possible Interactions with: Calcium
If you are currently being treated with any of the following medications, you should not use calcium supplements without first talking to your healthcare provider.
Calcium may interfere with the absorption of alendronate, a medication used to treat osteoporosis. Calcium containing products, therefore, should be taken at least two hours before or after alendronate.
When calcium citrate is taken with aluminum containing antacids, the amount of aluminum absorbed into the blood stream may be increased significantly. This is a particular problem for people with kidney disease in whom the aluminum levels may become toxic. In addition, aluminum-containing antacids may increase the loss of calcium in the urine.
Blood Pressure Medications
Taking calcium with a beta-blocker (such as atenolol), a group of medications used for the treatment of high blood pressure or heart disorders, may interfere with blood levels of both the calcium and the beta-blocker. Study results are conflicting, however. Until more is known, individuals taking atenolol, or another beta blocker, should have their blood pressure checked before and after adding calcium supplements or calcium containing antacids to their medication regimen.
Similarly, it has been reported that calcium may reverse the therapeutic effects as well as the side effects of calcium channel blockers (such as verapamil) often prescribed for the treatment of high blood pressure. These study results are also controversial. People taking verapamil or another calcium channel blocker along with calcium supplements should likely have their blood pressure checked regularly.
A class of medications known as bile acid sequestrants (including cholestyramine, colestipol, and colesevelam), used to treat high cholesterol, may interfere with normal calcium absorption and increase the loss of calcium in the urine. Supplementation, therefore, with calcium and vitamin D may be recommended by your healthcare provider.
Corticosteroid medications reduce the absorption of calcium, thereby increasing the risk for bone loss and osteoporosis over time. This is of particular concern for anyone who is maintained on long-term steroids.
High levels of calcium may increase the likelihood of a toxic reaction to digoxin, a medication used to treat irregular heart rhythms. On the other hand, low levels of calcium cause this medication to be ineffective. People who are taking digoxin should have calcium levels monitored in the blood closely.
Two different classes of diuretics interact with calcium in opposite ways—thiazide diuretics such as hydrochlorothiazide can raise calcium levels in the blood, while loop diuretics, such as furosemide and bumetanide, can decrease calcium levels. In addition, amiloride, a potassium-sparing diuretic, may decrease the amount of calcium excreted in the urine (and subsequently increase calcium levels in the blood), especially in people with kidney stones.
Estrogens may contribute to an overall increase in calcium blood levels. Taking calcium supplements together with estrogens improves gain in bone density significantly.
Taking calcium during treatment with the antibiotic gentamicin may increase the potential for toxic effects on the kidneys.
Metformin, a medication used to treat type 2 diabetes, can deplete levels of vitamin B12. Some early evidence suggests that calcium supplements may prevent or eliminate this negative effect of metformin. More research is needed.
Calcium can interfere with the body's ability to absorb quinolone antibiotics (such as ciprofloxacin, levofloxacin, norfloxacin, and ofloxacin). If taking calcium containing supplements or antacids, therefore, you should take them two to four hours before or after taking quinolone antibiotics.
Low levels of calcium have been reported with high doses of seizure medications, such as phenytoin, which may decrease calcium absorption. Some physicians recommend vitamin D along with anti-seizure drugs to try to prevent the development of low calcium levels.
Calcium can interfere with the body's ability to absorb tetracycline medications (including doxycycline, minocycline, and tetracycline) and, therefore, diminish their effectiveness. Calcium containing supplements and antacids should be taken at least two hours before or after taking these drugs.
Possible Interactions with: Magnesium
If you are currently being treated with any of the following medications, you should not use magnesium without first talking to your healthcare provider.
The absorption of quinolone antibiotics (such as ciprofloxacin and moxofloxacin), tetracycline antibiotics (including tetracycline, doxycycline, and minocycline), and nitrofurantoin is diminished when taken with magnesium supplements. Therefore, magnesium should be taken two to four hours before or after taking these medications to avoid interference with absorption.
Blood Pressure Medications, Calcium Channel Blockers
Magnesium may increase the likelihood of negative side effects (such as dizziness, nausea, and fluid retention) from calcium channel blockers (particularly nifedipine) in pregnant women. Other calcium channel blockers include amlodipine, diltiazem, felodipine, and verapamil.
Magnesium hydroxide, commonly found in antacids, may increase the absorption of glipizide and glyburide, medications used to control blood sugar levels. Ultimately, this may prove to allow for reduction in the dosage of those medications.
It is important that normal levels of magnesium be maintained while taking digoxin because low blood levels of magnesium can increase adverse effects from this drug. In addition, digoxin can lead to increased loss of magnesium in the urine. A healthcare provider will follow magnesium levels closely to determine whether magnesium supplementation is necessary.
Two types of diuretics known as loop (such as furosemide) and thiazide (including hydrochlorothiazide) can deplete magnesium levels. For this reason, physicians who prescribe diuretics may consider recommending magnesium supplements as well.
Hormone Replacement Therapy for menopause
Magnesium levels tend to decrease during menopause. Studies suggest, however, that hormone replacement therapy may help prevent the loss of this mineral. Postmenopausal women or those taking hormone replacement therapy should talk with a healthcare provider about the risks and benefits of magnesium supplementation.
There have been case reports of magnesium containing antacids reducing the effectiveness of levothyroxine, which is taken for an under active thyroid. This is important because many people take laxatives containing magnesium without letting their doctor know.
Penicillamine, a medication used for the treatment of Wilson's disease (a condition characterized by high levels of copper in the body) and rheumatoid arthritis, can inactivate magnesium, particularly when high doses of the drug are used over a long period of time. Even with this relative inactivation, however, supplementation with magnesium and other nutrients by those taking penicillamine may reduce side effects associated with this medication. A healthcare practitioner can determine whether magnesium supplements are safe and appropriate if you are taking penicillamine.
Tiludronate and Alendronate
Magnesium may interfere with absorption of tiludronate, a medication similar to alendronate that is used for the treatment of osteoporosis. This interaction has not been reported with alendronate specifically. Magnesium supplements or magnesium-containing antacids should be taken at least two hours before or two hours after taking these medications to minimize potential interference with absorption.
Aminoglycoside antibiotics (such as gentamicin and tobramycin), thiazide diuretics (such as hydrochlorothiazide), loop diuretics (such as furosemide and bumetanide), amphotericin B, corticosteroids, antacids, and insulin may lower magnesium levels. Please refer to the depletions monographs on some of these medications for more information.