7 Vitamins That Help Control Blood Sugar

B Vitamins

The B vitamins are especially important for glucose metabolism. They usually serve as cofactors in cellular reactions utilizing glucose. Therefore, they have been extensively studied to determine the benefits of controlling blood sugar levels.

Because the B vitamins are water-soluble, they are easily excreted from the body along with urine. This is especially important for diabetics as they easily develop deficiencies of the B vitamins.

1. Vitamin B1

Vitamin B1 or thiamine is a coenzyme in the metabolism of keto sugars. It is also important for the breakdown of pyruvic acid, a product released during glucose metabolism.

Therefore, vitamin B1 can help improve how cells utilize glucose. This can lead to better control of blood sugar levels. However, available studies do not always agree on the importance of vitamin B1 supplementation for diabetics.

Clinical data show that patients with Type 1 diabetes usually have low vitamin B1 levels and can, therefore, benefit from vitamin B1 supplements. 

On the other hand, Type 2 diabetes patients usually have normal blood levels of vitamin B1.

However, one study demonstrated that although diabetics have normal levels of this vitamin, its transportation across tissues is impaired. Therefore, even normal levels of the vitamin may not be sufficient to effectively control blood glucose levels in diabetics.

Vitamin B1 supplementation has been proven to prevent and treat neuropathy (nerve damage) caused by diabetes. Even then, doctors do not regularly prescribe it for their diabetic patients.

2. Vitamin B3

Vitamin B3 or niacin refers to a couple of vitamers: nicotinic acid and nicotinamide. These vitamers serve as coenzymes for several enzymes especially those involved in the metabolism of proteins, lipids, and carbohydrates.

Nicotinic acid is used in the treatment of hyperlipidemia because of its ability to break down lipids in the blood. However, it actually worsens glycemic control because it reduces carbohydrate tolerance.

Therefore, this form of vitamin B3 is not used in the treatment of diabetes although one study showed that its combination of chromium improved glucose tolerance in non-diabetic, elderly participants.

Nicotinamide, on the other hand, is especially useful in the treatment of Type 2 diabetes.

This form of vitamin B3 has been proven to protect the beta cells of the pancreas in newly diagnosed diabetic patients. By protecting these cells, this vitamer of vitamin B3 can sustain insulin production and help improve blood sugar control.

Studies show that nicotinamide is only useful for newly diagnosed cases of diabetes and especially in young Type 1 diabetes patients.

Overall, vitamin B3 does preserve beta cell functions in diabetics but its benefit for improving blood sugar control is still unclear. However, preserving beta cell functions is definitely a desirable outcome that can help improve insulin secretion and glucose utilization by cells.

3. Vitamin B6

Vitamin B6 or pyridoxine is another important coenzyme. It is important for amino acid and carbohydrate metabolism.

Vitamin B6 deficiency is common among diabetics and those with poor blood sugar control almost always have low plasma levels of vitamin B6. Also, clinical data show that diabetics who take insulin have lower vitamin B6 levels than those still placed on oral anti-diabetics. This shows that vitamin B6 levels get even lower as diabetes progresses.

Studies also show that vitamin B6 deficiency is strongly associated with glucose intolerance and reduced secretion of insulin and glucagon.

Since vitamin B6 is required for tryptophan metabolism, diabetics with low levels of the vitamin cannot properly metabolize tryptophan. This leads to the accumulation of intermediate products such as xanthurenic acid and hydroxykynurenine.

Xanthurenic acid binds to and inhibits insulin. This can directly translate to poor blood sugar control.

There is clinical evidence to show that vitamin B6 supplementation can improve glucose tolerance but only in those who have a vitamin B6 deficiency. However, most studies do not conclusively prove that vitamin B6 supplementation can affect blood glucose levels even though it may improve some other measures of glycemic control.

Experts agree that vitamin B6 supplementation can help prevent/relieve neuropathy (nerve damage) caused by diabetes. However, they advised against using megadoses of the vitamin since these can also cause neuropathy.  

4. Vitamin B12

Vitamin B12 is found in all cells. It is the most structurally complex of the B vitamins and it holds the distinction of containing cobalt.

Functionally, vitamin B12 is similar to folic acid, another B vitamin. Vitamin B12 deficiency can cause pernicious anemia, a condition that is commonly found alongside Type 2 diabetes especially in elderly patients.

Vitamin B12 deficiency is also associated with autoimmune diseases such as Type 1 diabetes.

While there are no studies to confirm that vitamin B12 supplementation can improve glycemic control, it can still be useful for diabetics. Injections of high-dose vitamin B12 can help prevent/relieve nerve damage caused by diabetes.

5. Vitamin C

Vitamin C or ascorbic acid is an antioxidant vitamin and an immune booster. It is involved in collagen synthesis and promotes wound healing.

Ascorbic acid and glucose use the same transport mechanism. Therefore, the hyperglycemia associated with diabetes can reduce the amount of vitamin C available to cells. However, glucose is not the only compound competing with vitamin C. Dehydroascorbic acid, a metabolite of vitamin C also competes with the vitamin.

Dehydroascorbic acid can damage nerves and worsen diabetes.

Studies show that while plasma vitamin C level is low in diabetics, plasma dehydroascorbic acid is usually high. Also, the levels of vitamin C in white blood cells and platelets are low in diabetics.

Therefore, a lower concentration of vitamin C can leave the insulin-secreting beta cells of the pancreas open to oxidative damage and autoimmune attack.

However, at least one study has concluded that 500 mg/dl (for 15 days) of vitamin C supplement did not improve blood sugar control in Type 2 diabetic patients. Some other studies found that high doses of vitamin C (and given for longer) did improve glycemic control.

One study also proved that vitamin C is rapidly lost in people with Type 2 diabetes. This high turnover means that diabetics must take higher than the daily dietary requirements of vitamin C to avoid being deficient in the vitamin.

The recommended dose of vitamin C for diabetics is 100 mg/day.

Supplementation with megadoses of vitamin C should be avoided because large doses of vitamin C interfere with blood glucose measurements and can, therefore, make it difficult for diabetics to closely monitor their blood sugar levels.

6. Vitamin D

Vitamin D is the only vitamin naturally synthesized in humans. Its bioactive form is known as calcitriol.

Its chief role is in the maintenance of bone density by regulating calcium and phosphate metabolism. Therefore, diabetics with low vitamin D levels have reduced bone mineral content.

Vitamin D deficiency is common with Type 1 diabetes although it can also affect those with Type 2 diabetes. This deficiency is associated with much-reduced serum levels of calcitriol, magnesium, calcium, and parathyroid hormone in diabetics compared to healthy subjects.

In one epidemiological study, researchers measured the vitamin D levels of the stored sera of over 2,000 participants who developed Type 1 diabetes. By comparing these measurements with the vitamin D levels of non-diabetic volunteers, the researchers found out that low vitamin D levels can increase the risks of Type 1 diabetes.

Some other studies also established that low vitamin D levels can increase insulin resistance and cause poor control of blood glucose levels in people with Type 2 diabetes.

Low serum levels of vitamin D can affect bone mass in children, the elderly, and women especially pregnant and lactating women with diabetes. The combination of diabetes and low vitamin D level can cause metabolic bone disease. Therefore, the vitamin D status of diabetics in these groups of diabetics should be regularly determined.

High doses of calcium and vitamin D supplements should be given to prevent bone diseases in diabetic patients.

7. Vitamin E

Vitamin E refers to a set of 4 related vitamers, the most important of which are alpha and gamma tocopherols.

It is an antioxidant vitamin. Its chief roles are to prevent the release of harmful free radicals and reactive oxygen species from the oxidation of vitamin A and unsaturated fatty acids. Therefore, the antioxidant properties of vitamin E may benefit diabetics.

In fact, studies investigating possible links between this vitamin and diabetes highlight the increased need for natural antioxidants such as vitamins E and C for diabetics.

These studies also prove that one of the ways by which the body reacts to the increased oxidative stress of diabetes is by increasing its store of vitamin E. The plasma and tissue levels of total vitamin E and alpha-tocopherol levels are higher in diabetics than in non-diabetics.

However, vitamin E levels in the platelets are usually lower. Given the importance of platelets to the immune system, vitamin E supplementation may be required to raise the concentration of vitamin E in the blood.

Furthermore, some studies have demonstrated that vitamin E supplementation can improve specific measures of glycemic control. For example, vitamin E can lower the level of glycosylated hemoglobin.

Besides reducing the levels of glycosylated hemoglobin, vitamin E supplementation can increase insulin sensitivity in Type 2 diabetes patients.

While there is a need for more studies on the benefits of vitamin E in the treatment of Type 2 diabetes, results from concluded studies strongly indicate that vitamin E supplementation can help diabetics achieve better control of their blood glucose levels.

Studies on Vitamin Supplementation in the Treatment of Diabetes

In a 1991 study published in the International Journal for Vitamin and Nutrient Research, a group of researchers compared the plasma concentrations of essential vitamins and nutrients between 100 type-2 diabetes patients and 112 non-diabetic patients.

The study result showed that diabetics usually have nutritional deficiencies and low levels of vitamins B1, B2, A, and E. Commonly reported mineral deficiencies involved in zinc and iron.

A 2006 study published in the journal, Molecular Nutrition and Food Research investigated the benefits of vitamins A, C, and E in reducing oxidative stress in diabetic rats. After inducing these rats with diabetes, they were given suboptimal doses of insulin while being supplemented with vitamins A, C, and E.

The study results showed that these antioxidant vitamins reduced the production of reactive oxygen species and improved the production of antioxidant enzymes especially superoxide dismutase.

This study supports the use of antioxidant vitamins in the management of diabetes and suggests that these vitamins can help prevent the complications of the disease.

Benefits of Mineral and Vitamin Combination for Diabetics

In a 2005 study published in the journal, Diabetes Care, a group of researchers compared the benefits offered by vitamin and/or mineral combinations in reducing kidney damage in type 2 diabetes patients. Sixty-nine type 2 diabetes were recruited for this study and divided into 4 groups.

The first group received a combination of zinc and magnesium; the second group was given vitamins C and E; the third group got a combination of the 2 minerals and 2 vitamins while the last group took a placebo.

The results of the study showed that the combination of both vitamins, as well as the combination of all 4 vitamins and minerals, significantly improve renal functions.

The same mineral and vitamin combination was investigated in a 2004 study published in the Journal of The American College of Nutrition. This study (an extension of the one described above) was designed to determine the effect of these vitamins and minerals on blood pressure in type 2 diabetes patients.

The researchers found that neither the combination of vitamins C and E nor the combination of zinc and magnesium reduced blood pressure. However, the combination of all 4 nutrients did reduce blood pressure.

These two studies demonstrate the benefits of vitamin and mineral supplementation to diabetics. Clearly, antioxidant vitamins and minerals can reduce the complications of type 2 diabetes.