What to Know About Vitamin D and Type 2 Diabetes Risk

Kasparas Aleknavicius

2021 Sep 10

10 min read

Vitamin D is a vital fat-soluble organic molecule that helps you maintain bone health and immunity. YES, it’s essential! But according to a report by the European Journal of Endocrinology, people diagnosed with type 2 diabetes experienced significantly increased peripheral insulin sensitivity and ß-cell function due to the vitamin D supplementation for six months. Suggesting that it may slow metabolic deterioration as well. 

The study consisted of 96 randomized patients. The double-blind, placebo-controlled trial included giving patients 5,000 international units (IUs) daily for six months. There are a bunch of other studies on vitamins for diabetics by experts. Many of them highlight a genuine link between diabetes and vitamin D. 

So, let’s get started with why Vitamin D is essential for our health and the link between Vitamin D and Type 2 Diabetes. Also, we will discuss How much Vitamin D should Diabetic patients take. 

How is Vitamin D helpful for our health?

Vitamin D is crucial for healthy bones, joints, and teeth. Besides that, it also helps to boost the immune system. According to Erin Palinski, author of The 2-day diabetes diet,  it helps in calcium absorption to promote bone health. Some additional studies also suggest that Vitamin D may play an important role in preventing disorders like diabetes. 

The study published in the American Journal of Clinical Nutrition suggests that this sunshine Vitamin may also help to reduce cholesterol levels. Keep in mind that people with type 2 diabetes are more prone to heart disease. People with diabetes are 2 times more likely to die from heart disease than people without diabetes. 

Vitamin D and Diabetes: What’s the link?

Both vitamin D deficiency and diabetes are pandemic diseases. Diabetes affects roughly 285 million people globally, or 7% of the global population, according to the International Diabetes Federation. By 2030, the population is predicted to top 435 million. Pre-diabetes affects over 79 million Americans.

Vitamin D insufficiency has recently come to light linked to an increased risk of type 2 diabetes. Many scientific studies and clinical trials say that vitamin D has an essential role in enhancing insulin sensitivity, a hormone necessary for blood glucose control. It is well established that a vitamin D level of 80 nmol/l or above is required to maintain proper glucose homeostasis.

Vitamin D insufficiency is thought to play a role in developing both type 1 and type 2 diabetes. First, VDRs and the one alpha-hydroxylase enzyme have been discovered in the β-cell of the pancreas, which secretes insulin. 

How vitamin D helps Type 2 diabetes patients?

Vitamin D supplementation has been shown to improve glucose tolerance and insulin resistance. Insulin secretion is lowered when vitamin D levels are low.  

In animals, vitamin D supplementation has been proven to restore insulin secretion. Indirect effects on insulin secretion have also been discovered, possibly due to a calcium effect. 

Low vitamin D may reduce calcium’s potential to alter insulin secretion by contributing to the normalization of extracellular calcium and guaranteeing normal calcium flow across cell membranes. 

Other possible mechanisms linked to vitamin D and diabetes include improving insulin action by stimulating insulin receptor expression, enhancing insulin responsiveness for glucose transport, having an indirect effect on insulin action via a calcium effect on insulin secretion, and improving systemic inflammation through a direct impact on cytokines.

Most studies demonstrate that vitamin D supplementation helps maintain a normal glycemic status by lowering insulin resistance, the leading cause of type 2 diabetes. The vitamin helps maintain an average glycemic level by reducing insulin resistance, the leading cause of diabetes.

How much Vitamin D should Diabetic patients take?

According to the research, an ideal level of 25-hydroxyvitamin D (25(OH)D in the blood (>80 nmol/l) requires a daily vitamin D dosage of more than 2000 IU. The risk of diabetes has been determined to be lowest at this level. The vitamin D status from both sun and food sources is commonly represented by 25(OH)D blood level.

A blood vitamin D level of less than 50 nmol/l has been linked to a two-fold increased risk of diabetes in older persons (over 70 years old). Furthermore, there is an inverse relationship between vitamin D levels and HbA1C, a well-known marker for poor glucose metabolism.

There are also specific vitamin D side effects associated with diabetes control. Studies have shown, for example, that maintaining an adequate vitamin D level over time is linked to weight reduction and a lower risk of obesity. And both of which lower the risk of diabetes.

Vitamin D has the potential to lower the risk of obesity in two ways. It can suppress hunger by raising blood leptin levels, necessary for fat storage regulation and satiety induction. Furthermore, it can lower parathyroid hormone levels in the blood, stimulating weight-loss mechanisms in the long run.

While you choose a Vitamin D supplement, make sure that the 3rd-party tests it. Also, please read the label carefully to know what it contains. You should opt for emulsion, drop, powders, and capsules to increase absorption chances.

Factors responsible for Vitamin D Deficiency

As you all know that Vitamin D intake is very important for balanced health, it depicts you should get it regularly. One of the major sources of Vitamin D intake is direct exposure to sunlight. 

Though it’s quite challenging to fulfil your Vitamin D requirements in this way, still it’s recommended by experts.

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According to NIH, you should sunbathe during maximum daylight time, typically from 11 am to 4 pm. Moreover, it is also recommended to soak yourself in sun rays for almost half an hour twice a week. 

What if you cannot get enough sunlight because of spending most of your time in indoor activities. Devje says that people can get vitamin D from sunlight even when their bodies are covered with clothes and sunscreen. It manifests you only need to prolong your outdoor exposure. 

A report presented by Harvard T.H. Chan School of Public Health showcases that people having darker skin absorb less vitamin D from sunlight because their skin color sunscreen naturally. Moreover, obese and overweight people are also at greater risk of Vitamin D deficiency, leading to diabetes. 

Diabetes-Friendly Foods: Source of High Vitamin D Intake

If you fail to get enough Vitamin D from sunlight, you should look for its food sources. Some primary sources of Vitamin D from food are eggs, cheese, mushrooms, a fortified diet (yogurt, milk, bread, cereals, and orange juice), and fatty fish (herring, salmon, and tuna). 

When the level of vitamin D in the body gets drastically low, doctors usually recommend supplements. It would be best if you never took any vitamin D supplements on your own. If you feel dizziness, pain, weakness, and other vitamin D deficiency symptoms, consult your doctor immediately.

Getting medical assistance is very important because the intake level of supplements depends upon the amount of vitamin D deficiency in your body. Also, visit a registered dietitian to get a diabetes-friendly healthy diet plan having meals rich in vitamin D. 


1- Can vitamin D reverse diabetes?

Yes, vitamin D can reverse diabetes’ effect to some extent by taking its regular dose in the form of supplements. Deficiency of Vitamin D is usually associated with severe diabetes, cancer, and cardiac disorders. Whenever the amount of Vitamin D gets lower in the body, the blood sugar level also increases. That’s why you should take vitamin D supplements to reverse diabetes to regulate insulin and blood sugar levels in the body. 

2- Can vitamin D deficiency cause peripheral neuropathy?

Peripheral neuropathy is a common disorder of nerve damage that occurs due to deficiency of Vitamin D. In this disease, vitamin D deficient people feel weakness, pain, and numbness in different parts of the body, including hands and feet. Low levels of vitamin D cause impairment of the brain and spinal cord and affect urination, circulation, and digestion. According to the National Health and Nutrition Examination Survey of 2001-2004, Vitamin D levels less than 30ng/ml cause diabetes type 2 and peripheral neuropathy in adults. 

3- Which vitamins are most important for a person with diabetes?

The following are some important vitamins for diabetic patients.

  • Chronic level of diabetes is due to deficiency of Vitamin D. Exposing diabetic patients to the sun 30 times a day increases Vitamin D levels that lead to reverse diabetes. 
  • Regular intake of Thiamin B1 is effective in relieving neuropathy pain and diabetes type 1 and 2. Eating nuts, grains, beef, eggs, oranges, cauliflower, and potatoes increase the level of thiamin B1 that regulates blood sugar level. 
  • Vitamin B12 also plays a vital role in improving diabetes and repairing nerve damage. Taking a regular dose of vitamin B12 orally controls the blood sugar level of diabetes. 
  • Vitamin E is also efficient in improving insulin efficacy. Taking regular doses of avocado, hazelnuts, almonds, nut butter, and sunflower seeds maintain blood sugar level. 
  • Low levels of Vitamin C can also be dangerous for people with diabetes. Its supplements lower blood sugar levels and increase insulin sensitivity. 

4- Do Vitamin K and D supplements help control blood sugar?

Vitamin K and D supplements are very helpful in controlling blood sugar levels. Various human studies have proven that Vitamin K supplements improve glucose tolerance, insulin sensitivity, prevent insulin resistance, and treat diabetes type 2. Moreover, Vitamin D supplementation is also potential in lowering blood sugar levels in diabetics. Taking in these supplements in the amount of 1000 IU daily for 12 weeks controls blood sugar levels. 

5- Can low vitamin D levels cause severe neuropathy?

Low levels of vitamin D are a risk factor for severe neuropathy and diabetes type 2 disease. Vitamin D deficiency causes nociceptor impairment by damaging nerves and lowering threshold pain. All signs of diabetic neuropathy can be reduced by taking in Vitamin D 3 once a week. 


Researchers are doing extensive research on vitamin D and type-2 diabetes. So, it depicts that the role of vitamins in preventing diabetes is worth debating. However, vitamin D does not contribute to controlling hyperglycemia. 

According to many studies, people can benefit from Vitamin D to control their blood glucose only if they face deficiency issues. However, if that’s not the case, diabetic patients may not benefit from Vitamin D supplementation. The maximum results are obtained when people are supplemented with ≥1000 IU of vitamin D for around 3 months. 

According to one study conducted on 2423 people, the dose of 4000 IU every day doesn’t prevent type 2 diabetes in people at high risk. The people involved are of different physical features like race, body mass, age, sex to prevent confusion. In the end, the results indicate that the people who developed type 2 diabetes in the vitamin D supplemented group and the control group were similar.

However, higher doses of Vitamin D can cause vomiting, nausea, and other complications. Along with that, people at higher risk of kidney and heart disease should know that excess intake of this vitamin can harden tissues and blood vessels. It can lead to kidney failure and heart damage, according to the NIH. So, it is better to consult your doctor before you start taking Vitamin D supplements.

If you’re unsure about whether you’re getting enough or too much vitamin D, consult your healthcare provider, who can give you blood tests to test for vitamin D deficiency or excess.

Written by

Kasparas Aleknavicius

Kasparas is one of our freshest doctor’s in the Klinio family. With his master’s in medicine and broad-spectrum health experience, he is helping our customers better understand diabetes management. Kasparas is also participating in every product project - from our blog and hub articles to diabetes management subtleties. As a healthcare futurist, he constantly looks for innovative ways to control blood glucose and ensure the most efficient diabetes management.

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