Supplements are used extensively in the general population. Approximately 40 percent of U.S. adults use at least one complementary and alternative therapy annually. Both consumers and health care provides should be aware of the many issues surrounding these products. It is important for both parties to be informed of the many factors that influence both safety and efficacy.
One of the main concerns with supplement use is that patients may assume that supplements are safe to use because they are “natural.” As a result, patients may neglect to ask their health care provider about potential medication interactions or adverse effects. Patients are using an increasing number of prescription drugs. When mixed with herbal and natural supplements there is an increased risk of a serious interaction. It is important to keep in mind that there is a shortage of reliable scientific information about how often drug supplement interactions occur and how significant they are.
Four questions need to be answered before a patient starts any supplement. Why is it being used? Is it safe? Are there interactions with my current medicines? Is it effective and what is the quality of the supplement chosen? Unfortunately, manufacturers of supplements do not need to perform the same safety and efficacy research that manufacturers of prescription medications need to do. Dietary supplements can be marketed without research on safety or effectiveness. They also do not need to go through the same quality control measures that a prescription medicine does.
This purpose of this article is to highlight the safety and efficacy of some of the most used supplements, and offer some evidence as to whether or not these supplements should or should not be recommended.
Garlic for Hypertension and Hyperlipidemia
Safety Rating: likely safe
Effectiveness Rating: possibly effective
Garlic is one of the most widely used supplements in the world today. For hypertension, some studies have shown that taking 200 mg to 400 mg of garlic three times daily can lower blood pressure by 2 percent to 7 percent after four weeks of treatment.
For hyperlipidemia, clinically, garlic use is not an effective way to decrease total serum cholesterol levels.
The potential benefits of garlic, even when statistically significant, is modest. The benefit needs to be weighed against the side effects associated with garlic. Proven adverse effects were malodorous breath and body odor. Other side effects include flatulence, abdominal pain, allergic reactions and an increased risk for bleed.
Garlic also has the potential to induce the cytochrome P450 system, creating a potential interaction with drugs like simvastatin (Zocor, Vytorin), atorvastatin(Lipitor), cyclosporine, oral contraceptives and many others. One study has shown garlic suppliments to decrease the levels of the HIV medicine saquinavir by about 50 percent.
Vitamin D
Safety Rating: likely safe
Effectiveness Rating: possilby effective
It is increasingly recognized that many adults in the United States are deficient in Vitamin D. Appropriate reverence levels of serum vitamin D forms are now available to health care providers. It is important for vitamin D levels to be checked, especially for patients on certain chronic medications or with chronic conditions. It is advised that all patients should ask their health care provider regarding their indication for testing and possible supplementation.
The tolerable upper intake level for vitamin D is 4,000 IU per day. Doses in excess of 4,000 IU per day may be used to correct deficiencies, but additional monitoring and medical supervision is recommended per the Institute of Medicine. Research also shows that taking a vitamin D supplement of 700 IU to 1,000 IU daily reduces the risk of falling. Many of the recent positive claims including cancer reduction continue to be investigated. What is clear is that this dietary supplement is rapidly becoming a primary focus of mainstream medicine.
As a side note, it is important to realize that many patients do not disclose their use of complementary and alternative medicine modalities or use of dietary supplements to their health care providers. Initiating a dialog with an appropriate discussion around vitamin D can open the door to expanded meaningful discussions.
Supplemental Calcium for Bone Health
Safety Rating: under evaluation
Effectiveness Rating: possibly effective
Recent studies have raised the question about calcium supplementation and cardiovascular health. The conclusion is that dietary and supplemental calcium is different. Advise patients to receive calcium from dietary sources for cardiovascular health.
In the World Health Organization study (WHI CaD) it was concluded that calcium plus vitamin D may provide modest protection for hip fracture for women aged 60 years or over. However, a WHI CaD reanalysis found that calcium plus vitamin D increased the risk of cardiovascular events in WHI CaD participants who were not taking personal calcium supplements at the time of randomization.
A recent prospective study also found that increased calcium intake from diet might not confer significant cardiovascular benefits, while supplements might raise MI risk.
Melatonin for Insomnia
Safety Rating: likely safe
Effectiveness Rating: possibly effective
Melatonin is a hormone produced by the pineal gland in the brain. At night, it plays a role in the regulation of the sleep-wake cycle. Melatonin levels have been shown to be below normal in some people with insomnia. It also has been shown to improve the sleep quality in elderly patients, especially if their melatonin levels are low.
Sedatives or hypnotics have many side effects including an increase for fall risk, especially in elderly patients. Melatonin may be a great alternative to try in patients with insomnia as it is generally well tolerated and has some data to prove its effectiveness.
Cinnamon for Diabetes
Safety Rating: likely safe
Effectiveness Rating: insufficient reliable evidence to rate
One proposed mechanism of action for cassia cinnamon is that it may increase insulin receptor sensitivity. The results of this study demonstrate that intake of 1 gram to 6 grams of cinnamon per day reduces serum glucose, triglyceride, LDL cholesterol, and total cholesterol in people with type 2 diabetes and suggest that the inclusion of cinnamon in the diet of people with type 2 diabetes will reduce risk factors associated with diabetes and cardiovascular diseases. This study was a driving factor for more studies related to cinnamon. Another meta analysis concluded that cinnamon does not appear to improve A1C, fasting blood glucose, or lipid parameters in patients with type 1 or type 2 diabetes.
Some cassia cinnamon products contain high levels of coumarin. Coumarin can cause hepatotoxicity in animal models. Very high doses of coumarin from 50 mg to 7,000 mg/day can result in hepatotoxicity that resolves when coumarin is discontinued.
Ginkgo Biloba for Memory
Safety Rating: likely safe
Effectiveness Rating: not effective
Ginkgo biloba has been proposed for use to improve memory and symptoms of Alzheimer’s disease.
A study published in JAMA in 2008 showed that ginkgo biloba at 120 mg twice a day has been shown to be effective in reducing either the overall incidence rate of dementia or Alzheimer’s disease incidence in elderly individuals with normal cognition or those with mild cognitive impairment.
Gingko might have antiplatelet effects and has been associated with several case reports of spontaneous bleeding. Due to its lack of evidence, and risk from potential side effects, ginkgo is not recommended for memory impairment.
