If you are living with prediabetes or type 2 diabetes, you know that there are several strategies your healthcare team may recommend to help lower blood sugar and HbA1c levels naturally.  Focusing on a healthy, balanced meal plan, managing stress levels, and getting enough daily activity and sleep are truly the pillars of good blood sugar management long term.

Even so, many people still turn to natural remedies to either support the recommended treatments of their care team or preemptively reduce their risk of developing type 2 diabetes. Dietary supplementation can provide added benefits for glucose control. This is especially true among people who may not get enough of the vital nutrients needed through their current nutritional plan to help manage blood sugar levels. 

The Role of Vitamins in Diabetes Management

There are vitamins and supplements available that are thought to help lower blood sugar and HbA1c levels in people with diabetes or prediabetes. Supplements can help fill in nutritional gaps, however, it is advisable not to have them become your primary source of vitamins and minerals. Whole foods in adequate amounts for your unique nutritional needs are always the best source of nutrients.

Also, the benefits of over-the-counter supplements remain largely unproven, and risky, according to the American Diabetes Association.  

Vitamin against yellow background

As with anything that has the potential to lower blood sugar and HbA1c levels, there is always a risk of you experiencing a very low blood sugar episode or hypoglycemia, especially in the elderly. There is also the potential for harmful interactions between supplements and any medications. 

So, the best practice is to check with your healthcare team or CoPilot IQ nurse before implementing any supplement regimen.  

If you decide to experiment with vitamins and supplements to lower your HbA1c levels, it may be wise to continually monitor your levels. Here is a convenient printable HbA1c chart and calculator to make it easy to monitor your levels at home, in between healthcare visits!

Key Vitamins for Lowering A1c Levels

Read on to discover what the current research says about 13 “anti-diabetes” supplements sold across the United States. Also, learn about how to use these supplements safely, taking into consideration any precautions, to make the most of your supplement plan!

Aloe Vera

Aloe Vera has long been thought to have blood sugar-lowering properties. A 2016 review of eight clinical studies found that oral Aloe Vera improved glycemic (blood glucose) control in people with prediabetes and type 2 diabetes. Even so, the researchers noted that the quality of the research was low and that more randomized controlled trials are needed to support the early findings.

Another review in 2016 suggested that Aloe Vera was particularly useful in lowering blood sugar levels in people with prediabetes. As with the other study, the authors conceded that the findings were inconsistent and that more research is needed before any recommendations can be made.

Aloe Vera Usage

Aloe vera comes in a juice form, as well as in extracts and dietary supplements. 

Aloe Vera Precautions

There are no guidelines for the appropriate use of Aloe Vera in any form, but it is recommended not to consume more than eight ounces (oz) of Aloe Vera juice daily to avoid diarrhea.

Aloe Vera juice has been shown to also cause hives and cramping. This is probably  due to latex found in the plant’s leaves. To avoid these symptoms, try to choose products made from the inner part of the Aloe Vera plant, called the “filet”, rather than the latex-rich leaves.

Aloe Vera can also interact with drugs like antidepressants and opioids. These interactions can either decrease the activity of the other drug, rendering it less effective, or can increase the activity of the other drug, increasing the risk of side effects.


A 2020 study suggested that cinnamon, made from the bark of the cinnamon tree, may help control blood sugar levels in people living with prediabetes.

The 12-week study published in the Journal of the Endocrinology Society evaluated 54 adults with prediabetes who were given either three daily 500-milligram (mg) doses of cinnamon or three daily doses of a placebo. According to the researchers, those who received cinnamon had lower sugar levels after overnight fasting than those given the placebo.

Cinnamon Usage

cinnamon sticks and powder

Cinnamon is taken by mouth as a supplement. Most manufacturers recommend doses ranging from 250 mg to 500 mg twice daily.

Cinnamon Precautions

When taken at high doses, cinnamon has been shown to cause heartburn, indigestion, burping, nausea, and diarrhea. Some types of cinnamon contain a compound called coumarin which can raise liver enzymes.   

If you have liver disease, it is in your best interest to consult with your healthcare team before taking cinnamon supplements.

Vitamin D

Vitamin D, or the “sunshine vitamin,” is generated when your body is exposed to the sun’s ultraviolet rays. If your levels are low, it can have wide-ranging negative effects on your body, including a higher risk of type 2 diabetes.

A 2019 study found that vitamin D may improve insulin sensitivity, lowering blood sugar levels and the risk of developing type 2 diabetes. The researchers examined 680 women in Brazil from the ages of 35 to 74. They found that vitamin D supplements decreased their blood sugar levels. Regular sun exposure was also tied to lower blood sugar levels, however.

A 2015 study found that a two-month regimen of taking daily vitamin D supplements resulted in participants having both improved fasting blood sugar and blood glucose levels. While emphasizing that more research needs to be conducted, the authors concluded that vitamin D supplementation may have beneficial effects on controlling the glycemic indicator.

Vitamin D Usage

It is best to consult with your care team about the best dosage of vitamin D for you before using it. It is recommended that you embrace a well-rounded, nutritional plan that includes vitamin D-rich foods to enjoy, like eggs and mushrooms. This ensures you will get all the nutrients your body needs.

Vitamin D Precautions

Vitamin D supplements may interact with various medications, including:

  1. Xenical, Alli (Orlistat): Weight loss drugs can reduce vitamin D absorption when included with a reduced-fat diet.
  2. Statins: Due to the fact that vitamin D is derived from cholesterol, various statins may actually impair vitamin D synthesis. There may also be a potential decrease in the absorption of certain statins with higher doses of the vitamin.
  3. Deltasone, Rayos, and Sterapred (prednisone): Steroids like prednisone that are prescribed for inflammation can reduce calcium absorption and impair the metabolization of vitamin D.
  4. Hygroton, Lozol, and Microzide (thiazide diuretics): When combined with vitamin D, which increases the body’s calcium absorption in your gastrointestinal tract, these diuretics can lead to hypercalcemia, where calcium levels are too high, particularly in older adults.

Some health risks have been associated with taking too much vitamin D. Too much vitamin D can result in kidney failure, but only in extreme cases. It can also result in the calcification of soft tissues like your heart valves, causing irregular heartbeats and even death.


Magnesium is a common mineral that plays a central role in regulating your blood pressure, muscle function, heart rhythm, and blood sugar levels.

In general, nutritional meal plans that include higher amounts of magnesium are tied to a lower risk of diabetes, which suggests it plays a significant role in sugar metabolism.

A 2019 study showed that taking oral magnesium supplements reduced participants’ resistance to insulin and improved glycemic regulation in people living with type 2 diabetes.

Magnesium Usage

Magnesium supplements come in different forms. Some include magnesium oxide and citrate, as well as chloride. It is recommended that you take magnesium with a meal each day for better absorption.

Magnesium Precautions

Magnesium supplements can interact with medications, including antibiotics and diuretics. It is wise to speak with your healthcare provider and give them a list of medications you’re currently on to avoid any interactions.

High doses of magnesium supplements can also cause nausea, abdominal cramping, bloating, and diarrhea. Magnesium oxide, chloride, gluconate, and carbonate are the forms that tend to cause diarrhea and other gastrointestinal problems the most. Taking large doses of laxatives and antacids that contain magnesium are tied to magnesium toxicity, as well.

Bitter Melon

Bitter melon, or Momordica charantia, is a fruit that has been used for medicinal purposes in Chinese as well as Indian medicine for centuries. It is often used as an herbal remedy for diabetes because it contains active anti-diabetic substances which are said to lower blood glucose levels.

There are not a lot of conclusive studies reviewing the impact of bitter melon on lowering blood sugar levels, but a 2011 report does suggest that bitter melon capsules contain at least one ingredient for inhibitory activity against the production of a specific enzyme—11β-HSD1. This inhibitory property is said to break down cortisone to the active form cortisol, a stress hormone, which can increase blood sugar levels. The authors theorize this might be why bitter melon is said to possess anti-diabetic properties.

The sample sizes of most studies included in a separate 2013 review were incredibly small. Therefore, It cannot be definitively said that bitter melon is as effective as more vetted supplements and herbal remedies for lowering blood sugar and HbA1c levels. The authors concluded that although research is encouraging, more studies to investigate the benefits of bitter melon are necessary.

Bitter Melon Usage

Bitter melon can be eaten as a whole fruit or squeezed into a juice, or its seeds can be crushed into powdered form for consumption. Bitter melon extract is also sold as an herbal supplement.

Bitter Melon Precautions

For those considering using bitter melon as a supplement to lower blood glucose levels, limit how much you eat or take, since consuming it in excess can result in diarrhea and  mild abdominal pain.

There also may be a risk of extremely low blood sugar dips, when taken along with insulin. One case report suggests that use of bitter melon could result in paroxysmal atrial fibrillation, where a rapid heartbeat begins suddenly and goes away on its own in seven days.


Gymnema, or Gymnema sylvestre, is a perennial woody vine found in tropical regions of India, China, Australia, and parts of Africa. It is often used in Ayurvedic medicine.

Research has shown that this plant can diminish a person’s craving for sugar. Additionally, it has been shown to lower the rate of the body’s sugar absorption, playing a large role in the treatment of diabetes.

One study out of 2017 looked at the impact of taking 200 to 400 mg of Gymnemic Acid. It showed that taking this substance actually reduced the intestines’ sugar absorption.

An earlier study in 2010 looked at participants with type 2 diabetes given 500 mg of Gymnema every day for a period of three months. The researchers found that the participants’ blood sugar levels after fasting and after meals lowered. Also, diabetic symptoms such as thirst and fatigue were less prominent, lipid levels improved, and glycated hemoglobin levels (HbA1c) decreased.

Gymnema Usage

Gymnema can be taken in the form of an extract, tea, or powder. You can also chew on the leaves of the plant itself and can find Gymnema in capsule form. If you opt for the capsule form of Gymnema supplements, you should consult with your healthcare provider to determine the best dosage for you.

Gymnema Precautions

Given that Gymnema can help regulate blood sugar levels in people with diabetes, it is important to stay on top of your blood sugar levels and monitor them regularly. Be on steadfast lookout for signs of low blood sugar episodes. This is especially true if you are taking other blood sugar-lowering medications, or insulin, at the same time.  Also, It is a good practice to work with your care team and let them know you are using this supplement before any surgical procedure, to ensure your levels do not dip too low.

Vitamins and supplements

American Ginseng

American Ginseng, also called Panax quinquefolius, is an herb commonly used in traditional Native American and Chinese medicine. It is believed the Ginseng plant’s roots can prevent infections and treat conditions like cancer and diabetes. American Ginseng might also lower blood sugar when used in conjunction with other herbs such as devil’s claw, ginger, guar gum, Panax ginseng, eleuthero, and fenugreek.

In general, American Ginseng has been found to be a relatively safe supplement.

One 2018 study of 39 people living with diabetes found that the herb, coupled with fiber, helped lower blood sugar levels over the course of 12 weeks. The authors clarified, however, that more research needs to be done to better understand the health impacts of this herbal supplement.

That was the similar conclusion of the authors of a 2014 review of 16 different studies. They looked at randomized, controlled trials that took place for a month or longer among people with and without diabetes. They found that those who used Ginseng herbal supplements had significantly improved blood sugar levels compared to the control groups.

American Ginseng Usage

You can get American Ginseng as an extract or in capsule form. As with other supplements, herbal treatments like Ginseng are highly unregulated and there is no standardized dosing to adhere to. For this reason, it may be best to speak with your healthcare provider about the best ways to incorporate this herbal supplement into your diabetes management plan.

American Ginseng Precautions

American Ginseng has been found to have moderate interactions with diabetes medications like insulin and sulfonylureas, including Amaryl (glimepiride), DiaBeta (glyburide), and Glucotrol (glipizide). These interactions could result in sudden low blood sugar episodes.

Ginseng products may also interfere with Coumadin (warfarin), a blood thinner.

Also, some people have reportedly experienced insomnia, diarrhea, headaches, and anxiety while using this herbal treatment. 


Chromium is a natural mineral found in certain foods. It comes in two forms: hexavalent (chromium 6+) and trivalent (chromium 3+). The trivalent form is what you will most likely encounter in food. The hexavalent form, however, is found in industrial waste and pollution.  Therefore this form should be strictly avoided.

A 2014 review found favorable effects of chromium supplementation on blood sugar control in patients living with diabetes. This was echoed years earlier by an older review that came to a similar conclusion. As with many of the supplements covered here, however, the authors did advise caution and that more research is necessary to better determine the health effects of chromium. 

Chromium Usage

There is no established Recommended Daily Allowance (RDA) for chromium. Generally, multivitamin or mineral supplements that contain chromium have doses of 35-120 mcg. You can also find supplements that are exclusively chromium, which provide 200 mcg to 500 mcg of the mineral. Some can go as high as 1,000 mcg, but they are not as common.

Chromium Precautions

Some medications may interact with chromium supplements. Insulin is one, as taking it with chromium increases the risk of low blood sugar episodes. Metformin and other diabetes medications taken together with chromium also carry this risk.

A small study showed that chromium picolinate supplements taken at the same time as the hypothyroidism treatment levothyroxine can delay that drug’s absorption by over six hours.

Individuals with kidney and liver disease may suffer from worse symptoms of their condition if they take a lot of chromium. Some isolated symptoms include weight loss, anemia, liver dysfunction, thrombocytopenia, kidney failure, rhabdomyolysis, and dermatitis. 


Berberine is included in a wide range of supplements and has been a staple of traditional Chinese and Indian medicine. It’s been used in the treatment of type 2 diabetes, hypertension, and hyperlipidemia.

A 2019 study examined 80 people who were in the hospital for metabolic syndrome from January 2017 to December 2017. The researchers concluded that berberine-based therapy regulated blood glucose and alleviated insulin resistance.

A 2014 meta-analysis concluded that berberine is a good option for treating conditions like type 2 diabetes in people of lower socioeconomic status because it’s relatively low cost and effective with no serious side effects. 

As with other herbal supplements, more research on the benefits of berberine needs to be conducted.

Berberine Usage

Taking 500 mg of berberine two to three times a day for up to three months could be an effective way to control blood sugar levels.

Berberine Precautions

Berberine does have some interactions with medications you may already be taking. Keep in mind this is not an exhaustive list and that there may be other interactions:

  1. Neoral, Sandimmune (cyclosporine): Berberine may decrease the speed with which your body breaks down this medication, which could cause it to build up and exacerbate side effects.
  2. Diabetes medications: Berberine may lower your blood sugar levels, and when paired with other blood sugar-lowering drugs, you could be at risk for sudden low blood sugar episodes.
  3. Robitussin DM (dextromethorphan): Berberine could reduce your body’s ability to quickly break down dextromethorphan.
  4. Blood thinners (anticoagulants or antiplatelets): Given that berberine may slow down blood clotting, taking it along with blood thinners may exacerbate this process, increasing risk for bleeding and bruising.

Berberine has been found to also cause some gastrointestinal problems like diarrhea, cramping, or constipation. 

Alpha-Lipoic Acid

Alpha-lipoic acid is a compound found inside each cell in the human body. It converts your glucose into energy by way of oxygen. This is called aerobic metabolism. 

In general, alpha-lipoic acid is fairly safe to take and side effects are rare.

A 2012 study surveyed 38 people with type 2 diabetes who were put on daily 300, 600, 900, and 1,200 mg treatments of alpha-lipoic acid over six months. After treatment, the participants were monitored for their glucose status and oxidative biomarkers. The researchers found that these individuals’ fasting blood sugar and HbA1c levels decreased in measure with dosage increase.

A 2019 review examined a series of studies on the effectiveness of alpha-lipoic acid. The analysis offers a mixed bag. While some of the research was encouraging, others showed alpha-lipoic acid to be no more effective than placebos administered to participants. Overall, the authors suggested that more studies with larger sample sizes are needed to determine effectiveness.

Alpha-Lipoic Acid Usage

Dosage in capsule form of alpha-lipoic acid greatly varies. One study cited a dosage range from 600 mg to as high as 1,200 mg daily before eating.

Alpha-Lipoic Acid Precautions

Alpha-lipoic acid can interact with some medications, including diabetes medications, chemotherapy medications, thyroid medications, and vitamin B1. Also, given that alpha-lipoic acid can lower blood sugar levels, people with already low blood sugar levels should consult with your healthcare team before adding this to their daily regimen. 

Even though side-effects are rare, they can still occur. Known side effects include fatigue, diarrhea, skin rash, and insomnia. 


Probiotics are healthy bacteria found in certain fermented foods that may help reduce blood sugar in people with diabetes. These “good” bacteria help support the natural environment of bacteria and fungi in the gut and, by doing so, aid in the digestion of carbohydrates that might otherwise give rise to high blood sugar spikes.

In addition to probiotic foods, there are a number of probiotic supplements available that can deliver these “good” bacteria to your body in a large concentrated dose.

A 2021 review of studies involving 20 randomized controlled trials and 2,972 participants concluded that probiotic supplements were especially good in managing blood surgery in people with gestational diabetes, the type that can develop during pregnancy.

Probiotics Usage

In addition to supplements, probiotics are found in the following fermented foods :

  • Yogurt
  • Kefir
  • Sauerkraut
  • Kimchi
  • Pickles

When taken as a supplement, a daily dose of between 10 to 20 billion CFU (colony-forming units) is considered safe and effective in maintaining a healthy balance of bacteria in your gut.

Probiotics Precautions

Even though probiotics are generally considered safe, they may still cause some side effects. These include mild stomach upset, diarrhea, gas, and bloating. These tend to occur during the first few days of treatment but have been found to generally subside as your body gets used to the supplements.


Nigella sativa, also known as black cumin seed or “black seed”, is a naturopathic remedy thought to have blood sugar-lowering properties. Nigella sativa is generally regarded as safe when used for culinary purposes or taken as a daily supplement. Proponents suggest that it can treat a wide range of medical conditions, including high blood pressure, skin infections, diarrhea, and liver disease.

A 2019 review of studies suggested that Nigella is able to lower blood sugar in people with type 2 diabetes by increasing not only insulin sensitivity but overall insulin levels. The compound thought to effect these changes is an essential oil known as thymoquinone. 

Nigella Usage

Nigella supplements are sold online and in many drugstores and supplement shops. The manufacturer’s recommended daily intake is between 1,000 and 2,000 mg per day taken in a single dose. The supplement is typically sold as a gel cap containing black cumin seed oil.

Nigella Precautions

Even though Nigella sativa is considered generally safe,  it has been shown in some to cause stomach upset, gas, bloating. nausea, vomiting, or constipation, especially when taken at higher doses.

It can also interact with certain drugs used to treat high blood pressure. If you are being treated for high blood pressure, speak with your healthcare provider before using Nigella sativa.


Researchers have long recognized that many people with type 2 diabetes have zinc deficiency, leading some to assume that zinc supplements may help improve blood sugar control.

To date, the evidence of this remains mixed. Although a 2015 review of studies suggested that zinc supplements (ranging from 5 to 50 mg) showed promise in managing blood sugar in people living with type 2 diabetes, neither the findings nor the quality of the studies were consistent. 

Even so, the use of zinc supplements was considered reasonable given the many complications that can arise with zinc deficiency. These can include vision problems, fatigue, skin changes, and an increased risk of infection.

Zinc Usage

The recommended daily intake of zinc from all sources is 11 mg per day for adult males and 8 mg per day for adult females.

In addition to supplements, excellent food sources of zinc include:

  • Oysters
  • Red meat
  • Fish
  • Beans
  • Nuts
  • Dairy
  • Whole grains

Zinc Precautions

You generally cannot “overdose” on zinc because it is readily excreted from the body in urine. Even so, taking high doses all at once may cause side effects like headache, nausea, stomach upset, diarrhea, and vomiting.

Zinc can also interfere with the absorption of nonsteroidal anti-inflammatory drugs (NSAIDs) like Aleve (naproxen) and Indocin (indomethacin), making these painkillers less effective.

Tips For Adding Supplements

Keep in mind that you may experience different results than what the above studies have found based on factors such as duration, supplement quality, and your individual diabetes status.  

Here are a few tips:

  1. Monitor your blood sugar levels regularly-keep a log book of new patterns! 
  2. Try one supplement at a time so you can determine the impact of that one supplement on your blood sugar levels. Then try another if need be.
  3. You may find that your care team will have to make adjustments to medications from time to time once you start taking supplements. Keep the lines of communication open!
  4. If you are taking other diabetes medication or insulin, take note of any side effects you may encounter and share with your care team to avoid any harmful interactions.

There are many supplements available that may help lower blood sugar and HbA1c levels. Adding vitamins and supplements to your current diabetes management plan of balanced nutrition, regular exercise and quality sleep may be all you need to reach your unique diabetes management goals.

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