You may have taken multivitamin supplements once in your lifetime to fulfill your nutritional deficiencies. Vitamins help maintain your bones, joints, hair, and skin. They also assist your body to perform vital functions such as digestion, circulation, and excretion. However, the overuse of vitamins can lead to potential health complications. The role of vitamins in diabetes is different from that of healthy individuals. So, what vitamins diabetics should avoid?

This article gives a detailed overview of vitamins that diabetic individuals shouldn’t take and why.

What Vitamins Should Diabetics Avoid?

Micronutrients, including vitamins and minerals, work as cofactors and coenzymes in fat, proteins, and carbohydrate metabolism. Therefore, vitamins can improve as well as complicate your diabetes. 

Also, healthcare practitioners do not promote the consumption of vitamin supplements for diabetic individuals until or unless there is a nutritional deficiency. Moreover, the mechanism of action of vitamin supplements is different for diabetics than for the healthy population.

To better understand what vitamins diabetics should avoid, let’s go into their details one by one.

Vitamin E

Vitamin E is among the water-insoluble vitamins that are known for their antioxidant properties. Antioxidants tend to protect your cells by preventing damage caused by oxygen-free radicals. Moreover, people with diabetes might require adequate antioxidants due to the heavy production of free radicals. It happens because of consistently high glucose levels in the bloodstream.

However, vitamin E supplementation is not recommended for diabetic individuals. In contrast, people who are using Orlistat for diabetes may require vitamin E supplements because this medication doesn’t allow effective absorption of vitamin E. Moreover, the daily use of 400 IU vitamin E is usually considered safe by healthcare practitioners. Vitamin E contains anticoagulant properties, and if you intake over 800 IU of vitamin E, it may lead to unnecessary blood thinning. 

Additionally, you have to be extra cautious of taking vitamin E if you’re consuming anticoagulant agents, including aspirin, warfarin, and ginseng, because it can increase your chances of getting internal bleeding. It may also lead to blood sepsis (infection) that can be life-threatening in certain situations. 

Vitamin B3

Vitamin B3 is a water-soluble vitamin known as nicotinic acid and nicotinamide. It plays a pivotal role in maintaining fat, carbohydrate, and protein metabolism. 

Moreover, vitamin B3 deficiency can cause a triad of dermatitis, dementia, and diarrhea. If it is not treated, it can be lethal.

However, if you ask about what vitamins diabetics should avoid, vitamin B3 is one of them. The use of vitamin B3 doesn’t bring any satisfactory results to the patients. The high dosage of vitamin B3 negatively impacts the glycemic control of diabetic individuals. 

In contrast to heavy dosage, the small quantity of vitamin B3 has brought good results to diabetic individuals. It also helps in lowering the concentration of bad cholesterol and triglycerides and aids in increasing the concentration of good cholesterol in diabetic dyslipidemia.


Apart from vitamins that diabetics should avoid, certain minerals are unhealthy for diabetics, and one of them is chromium. Chromium is an essential nutrient, and its concentration may influence insulin action in the body. 

Healthcare practitioners avoid recommending chromium supplementation due to its inconclusive effects on diabetics. In contrast, chromium, when used with other treatments may reduce fasting plasma glucose and HbA1c concentration slightly in diabetic individuals. However, clinically, the positive effects of using chromium in diabetic individuals remained unclear. 

Moreover, if you have diabetes, you are at greater risk of developing kidney diseases. For that reason, chromium is not prescribed to diabetics because it tends to destroy your kidney health, which may lead to renal failure. 

Also, chromium is more likely to interfere with the absorption of other minerals and disturb their function. For instance, high doses of chromium are associated with decreased absorption of zinc and iron, which may cause skin reactions, indigestion, and stomach pain in diabetic individuals.


Selenium is among the essential trace elements that help in DNA repair and synthesis. It also helps in regulating thyroid function, antioxidant defense, and immunity. 

However, there is no effect of selenium supplementation in diabetic individuals. In addition, consuming heavy doses of selenium in the long term may result in causing nail and hair loss. It can also damage to your nervous and gastrointestinal systems. 


These fatty acids are the key components of fish oil. Omega-3 helps lower triglycerides and cholesterol levels, thereby preventing cardiovascular diseases. However, the effects of omega-3 have not been satisfactory in diabetics. 

In addition, diabetics who are using blood-clotting medications should be aware of potential drug interactions of omega-3. It can cause blood thinning that may lead to internal bleeding in the worst cases. 

Herbal Supplementations

Besides what vitamins diabetics should avoid, there are certain herbal supplementations that are not good for your blood sugar. These include:

St. John’s Wort

St. John’s Wort supplement can cause multiple drug interactions that may be harmful to diabetes. It can negatively react with metformin and anticoagulant medications that are widely used to treat diabetes and cardiac disorders. 

Anticoagulant medications such as warfarin, apixaban, dabigatran, heparin, and rivaroxaban, if used with St. John’s wort supplements, can increase your risk of bleeding. Moreover, St. John’s wort decreases the renal clearance of melatonin from your body and it stays in your system for a longer period which makes you prone to get its side effects. 

Prickly Pear Cactus

Prickly pear cactus is an edible fruit filled with essential nutrients such as vitamins B & C, calcium, and zinc. It is also effective in treating vitamin deficiencies. However, prickly pear cactus is not a favorable supplement to use with diabetes medications. It alters blood sugar levels and may lead to adverse hypoglycemia reactions. 


Ginseng is a medicinal herb used to increase libido, fertility, sperm count, and testosterone hormone concentration in males. However, ginseng tends to decrease blood clotting. If it is consumed alongside anticoagulants, it may result in excessive blood thinning and may cause bleeding in diabetic individuals.


Therefore, you must carefully follow what vitamins diabetes should avoid to limit harmful drug interactions. Moreover, you should seek consultation from a healthcare professional before using any vitamin and herbal supplementations to keep your blood sugar under control. 

Which Vitamins Should Diabetics Consume?

Besides what vitamins diabetics should avoid, there are a few vitamins that have brought beneficial results to control your blood sugar. It includes:


If you’re suffering from diabetes, you’re most likely to have decreased concentration of thiamin in your bloodstream. It also puts you at risk of developing thiamin deficiency. Thiamin, also known as vitamin B1, helps to maintain nerve health.

Moreover, neuropathies (nerve injuries) are among the common complications of diabetes. Thiamin supplementation helps to improve the symptoms of diabetic neuropathy. 

Thiamin is naturally found in nuts, beef, whole grains, cauliflower, eggs, kale, potatoes, and asparagus. Add these foods to your meals to fulfill your daily thiamin requirement. 

Vitamin B12

Vitamin B12 regulates healthy red blood cells and supports brain function. People with diabetes are more likely to develop peripheral neuropathy, a disorder that causes nerve damage in the hands and feet. Vitamin B12 deficiency may worsen its symptoms. Therefore, taking vitamin B12 is necessary to treat this condition. 

You can get vitamin B12 naturally from meat, eggs, milk, and fish. However, if you’re vegetarian or vegan, you may fulfill your daily vitamin B12 count by taking oral supplements. 


What Vitamins Raise Blood Sugar?

If you consume niacin (vitamin B3) on an empty stomach, your fasting glucose levels are more likely to get high. Therefore, vitamin B3 is not recommended for diabetic individuals as its risk outweighs its benefits. 

Why Should Diabetics Not Take Vitamin C?

Vitamin C supplements are not associated with consistent glycemic control in diabetic individuals, especially in people who are suffering from type 2 diabetes. In contrast, vitamin C contains a good amount of antioxidants that may improve the complications of diabetes. Additionally, consuming heavy doses of vitamin C may put you at higher risk of getting cardiovascular diseases.

Is Vitamin D Bad For Diabetics?

No. In contrast, people with vitamin D deficiencies are more likely to develop complications of diabetes. Therefore, eating a vitamin D-rich diet, including fatty fish, egg yolk, dairy products, and UV-exposed mushrooms, enables you to fulfill its deficiency during diabetes. Moreover, getting 5 to 30 minutes of sun exposure, depending on your skin type and climate, aids you in storing vitamin D naturally. 

The Bottom Line – What Vitamins Diabetics Should Avoid 

If you have diabetes, you should remain very cautious when consuming any dietary vitamins. Vitamins can negatively interact with your diabetes medication, which may cause further health complications. Moreover, the dosage of your vitamins also affects your kidney health, which is prone to diabetes. Therefore, discuss with your healthcare practitioner what vitamins diabetics should avoid before consuming them.


This content is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions. Neither Abraham Parker, nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any nutrition, supplement or lifestyle program.

Published On: March 22nd, 2024 / Categories: Diabetes diet and nutrition / Tags: /