The Safety of Nutrient Supplements
Melissa Diane Smith, Dipl Nutr.

Generally speaking, nutrient supplements are safer (and less expensive) than pharmaceutical drugs, which often can have serious side effects (and can be pricey). Therefore, nutrient supplements usually can be tried first before medications in beginning or mild cases of diabetes. Many nutrients can also be used together with prescription medications to support patients in later stages of the disease.

However, some nutrient supplements are safer than others. This article will cover the safe doses and uses of nutrient supplements, so you can use them thoughtfully and carefully to improve your patients’ health.

 

Nutrients That Have Low-Dose Limits

We need more than a dozen nutrients--vitamins and minerals from A to zinc--on a daily basis for health. But we need to be more careful in supplementing with some nutrients than others.

Selenium is one of those nutrients that has low-dose limits. It is a powerful antioxidant mineral that works in concert with vitamin E, another antioxidant, reducing the free radical stress that is part and parcel of diabetes. It also helps boost immunity and protects against the development of heart disease and cancer—all good reasons to recommend that people with diabetes supplement with it. But supplemental selenium should not be overdone. A daily dosage of 200 mcg is considered safe and adequate for the average American adult. Taking more than 800 mcg daily, on the other hand, could be hazardous. This is a good example of when more definitely is not better. Make sure your patients follow the recommended intakes to reap the benefits of selenium without any risk to their health.

Copper is another essential mineral with a low-dose limit. Along with zinc, copper is part of an antioxidant enzyme called superoxide dismutase, or SOD, which keeps free radicals in the body in check. However, an excess of copper can increase free radical activity in the body. Research shows that people who have diabetes tend to have higher copper levels and lower zinc levels than people who don’t have diabetes. Also, people with diabetic complications such as retinopathy, hypertension, or microvascular disease tend to have higher copper levels than people without diabetic complications. For these reasons, I generally recommend that people who have diabetes or prediabetes get adequate copper from the food they eat (from nuts and seeds especially) and avoid supplementing with copper unless they have been diagnosed with a documented copper deficiency. Even for people who take high doses of zinc between 30 to 50 mg per day, doses of copper generally should not exceed 2 mg per day. Possible symptoms of excessive copper intake include greater susceptibility to infection, insomnia, and feelings of depression or anxiety.

Iron in excess also can increase free radical activity, thereby oxidizing and damaging tissues, aging the body, and greatly increasing the risk of degenerative diseases. To be on the safe side, I believe it’s best to avoid recommending supplements with iron unless your patients have been diagnosed with a legitimate iron deficiency by means of a serum ferritin test.

Nutrients with Cautions

As mentioned in Part 1, vitamin E is the principal fat-soluble antioxidant in the body and a key protector against cardiovascular disease. It, therefore, is quite beneficial for those with diabetes and prediabetes. For most people, natural vitamin E (as indicated as d-alpha tocopherol on the bottle label) also is quite safe in doses of 400-800 IU. But some caution is required in those with diabetes or other health conditions.

First, if your patients are taking insulin or hypoglycemic drugs, you may have to work with their physicians to reduce the dosage of these drugs. Second, people with high blood pressure should regularly monitor their blood pressure, starting with lower doses of vitamin E and gradually building up to 400 IU. Third, people with rheumatic heart disease, in which half the heart is damaged, should start taking only 50-100 IU of vitamin E under a physician’s supervision. And lastly, people with “leaky” blood vessels, such as in some types of diabetic retinopathy (eye disease)—or people who take prescription anti-coagulants (blood-thinning drugs)—could develop problems with vitamin E supplements, due to the nutrient’s mild (and normally beneficial) anti-clotting properties. While such problems are not common, caution is warranted.

Magnesium, a mineral that helps protect against cardiovascular disease and hypertension, is safe for most people at a dose of 200-400 mg per day. However, there is an important caveat: Too much supplemental magnesium can be dangerous for a patient who has diabetic kidney disease or other serious kidney dysfunction. If a patient of yours has one of these conditions, do not recommend magnesium supplements unless you consult and work closely with his or her physician.

Supplementing with niacin, or vitamin B-3, can be extremely therapeutic for control of blood fats, reducing high LDL cholesterol levels and blood triglycerides and raising HDL cholesterol levels. But niacin generally isn’t a good therapy for people with diabetes. That’s because it impairs glucose control, sometimes raising fasting blood sugar levels above 200 mg/dL. For most people with diabetes or prediabetes, it’s best to avoid supplementation with niacin alone and take low to moderate doses of niacin (or niacinamide) in a balanced B-complex or multivitamin/mineral supplement that contains all the B vitamins.

Nutrients with Far Greater Safety

Chromium and alpha-lipoic acid, which I think should be essential components of a nutrient supplement program for those with diabetes or prediabetes, require far less caution. In animal experiments, chromium has demonstrated a lack of toxicity at extremely high levels—levels several thousand times the estimated safe and adequate daily dietary intake (ESADDI) limit of 200 mcg per day. There also is no evidence of toxic effects related to chromium supplementation in humans or animals. In fact, research shows that rats deprived of chromium have shorter life spans, while rats supplemented with chromium picolinate live 37 percent longer than they do in their natural habitat. And type 2 diabetic patients who have taken 1,000 mcg chromium (as chromium picolinate) per day have experienced spectacular improvements in their condition without any adverse side effects.

No upper limit for chromium has been established, but the highest dose used in studies with humans has been 1,000 mcg per day. Some doctors have noticed an energizing effect that may keep people up if chromium is supplemented in the evening, but that can be remedied by taking supplemental chromium earlier in the day.

The form of chromium is particularly important as it relates to efficacy and safety. As I discussed in Part 1 of this series, chromium picolinate is the preferred form due to its superior bioavailability, safety record, and extensive clinical data in people with diabetes.

Animal and human studies also provide compelling and consistent evidence that alpha-lipoic acid supplementation is exceptionally safe for the general population in amounts of 50 to 100 mg per day. Serious side effects have also not been shown, even at high doses. The minor side effects that have been experienced in humans include skin reactions and gastrointestinal effects such as nausea and vomiting. However, these effects have generally been noted in a small percentage of subjects who received intravenous infusions of 1200 mg or more of alpha-lipoic acid per day—amounts more than 12 times the typical amount for use as a daily antioxidant supplement. Alpha-lipoic acid is currently approved in Germany as a drug for use in the treatment of diabetic polyneuropathy at a dose of 600 mg per day.

As with vitamin E, the main caution in recommending supplementation with chromium picolinate or alpha-lipoic acid is with your diabetic patients who take insulin or hypoglycemic drugs. Both chromium picolinate and alpha-lipoic acid supplementation help insulin work more efficiently and may reduce drug requirements. So people with diabetes who take these drugs should work with you or their physician to gradually increase their doses of these nutrients while you or their doctor monitor their condition and adjust their drug requirements. This is a good thing, of course: it indicates an improvement, or reversal, of the insulin resistance at the root of their disease, but it does require some caution to help prevent your patients from overmedicating.

In Part 3 of this article series, I’ll cover new nutritional agents that are proving helpful for those with diabetes and prediabetes.

Parts of this article were excerpted and adapted from Chapters 5 and 6 in User’s Guide to Preventing and Reversing Diabetes Naturally (Basic Health Books, June 2003) by Melissa Diane Smith.

Melissa Diane Smith is a leading nutritionist, health writer and educator who counsels clients across the country and specializes in sugar- and grain-related health conditions. She’s the author of User’s Guide to Preventing and Reversing Diabetes Naturally (Basic Health Books, 2003), Going Against the Grain (McGraw-Hill/Contemporary Books, 2002), and User’s Guide to Chromium (Basic Health Books, 2002) as well as coauthor of the national bestseller, Syndrome X: The Complete Nutritional Program to Prevent and Reverse Insulin Resistance (John Wiley & Sons, 2000). For more information on her books or her practice, visit www.melissadianesmith.com. To be notified when her new book will be ready please email info@melissadianesmith.com with a subject line of “Diabetes Guide Notification.”

Selected References

1. Anderson RA, Chen N, Bryden NA, et al. Elevated intakes of supplemental chromium improve glucose and insulin variables in individuals with type 2 diabetes. Diabetes, 1997;46:1786-1791.
2. Challem J, Smith, MD. User’s Guide to VitaminE. North Bergen, NJ: Basic Health Publications, 2002.
3. Cheng N, Zhu X, Shi H, et al. Follow-up survey of people in China with type 2 diabetes mellitus consuming supplemental chromium. The Journal of Trace Elements in Experimental Medicine, 1999; 12:55-60.
4. Konrad T, Vivina P, Kusterer K, et al. a-lipoic acid treatment decreases serum lactate and pyruvate concentrations and improves glucose effectiveness in lean and obese patients with type 2 diabetes. Diabetes Care, 1999;22:280-287.
5. Rindone JP, Aachacoso S. Effect of low-dose niacin on glucose control in patients with non-insulin-dependent diabetes mellitus and hyperlipidemia. American Journal of Therapies, 1996; 3:637-639.
6. Walter RM, Uriu-Hare JY, Olin KS, et al. Copper, zinc, manganese and magnesium status and complications of diabetes mellitus. Diabetes Care, 1991;14:1050-1056.
7. Ziegler, et al. Treatment of symptomatic diabetic peripheral neuropathy with the anti-oxidant a-lipoic acid. A 3-week multicentre randomized controlled trial (ALADIN Study). Diabetologia, 1995;20:369-373.
8. Ziegler D, Gries FA. a-Lipoic acid in the treatment of diabetic peripheral and cardiac autonomic neuropathy. Diabetes, 1997;46 (Suppl. 2): 62-66.

Melissa Diane Smith is a leading nutritionist and health writer who counsels clients across the country and specializes in sugar- and grain-related health conditions. She’s the author of User’s Guide to Preventing and Reversing Diabetes Naturally (Basic Health Books, 2003), Going Against the Grain (McGraw-Hill/Contemporary Books, 2002), and User’s Guide to Chromium (Basic Health Books, 2002) as well as coauthor of the national bestseller, Syndrome X: The Complete Nutritional Program to Prevent and Reverse Insulin Resistance (John Wiley & Sons, 2000). For more information on her books or her practice, click here www.melissadianesmith.com.

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