Are You Getting Enough of These Nutrients?

Nutrition plays a key role in helping you stay healthy and lowering your risk of certain diseases. Since no one food provides all of the nutrients that you need, the general advice is to eat a variety of foods, including vegetables[1], fruits[2], whole grains[3], protein foods and healthy fats. But in reality, not everyone follows this advice.


How can you be sure you’re getting the nutrition that you need? Is the answer to swallow a handful of supplements? Not necessarily. While some people can benefit from dietary supplements, such as certain vitamins and minerals, there’s a risk of overdoing it (the “if some is good, more is better” thinking). The advantage to choosing food over supplements is that whole foods contain other substances that supplements don’t have, namely fiber and phytonutrients.


There are people who can benefit from supplements, and these include:

If you’re wondering if you should take any kind of dietary supplement, it’s always best to discuss this with your healthcare provider or registered dietitian. Likewise, if you currently take supplements, don’t forget to let your healthcare team know.

In the meantime, here are several nutrients that you might not be getting enough of. These nutrients may play a role in managing diabetes, warding off certain diseases or complications of diabetes[4], or promoting overall health.

To get cutting-edge diabetes news, strategies for blood glucose management, nutrition tips, healthy recipes, and more delivered straight to your inbox, sign up for our free newsletter[5]!


Think of calcium and you probably think of “bones.”[6] For sure, calcium is a mineral that is necessary for strong bones and teeth. It’s particularly important for people with diabetes to get enough, as they have a higher risk of osteoporosis than people without diabetes. Bones aside, muscles and nerves require calcium to function properly, and calcium helps blood vessels move blood throughout the body.

How much do you need?

Men and women between the ages of 19 and 50 years need 1,000 milligrams (mg) of calcium[7] daily; women age 51 to 70 need 1,200 mg, and both men and women 71 years of age and older need 1,200 mg.

Food sources

Milk, yogurt and cheese are the main sources of calcium, but you can get calcium from canned sardines and salmon, kale, broccoli and fortified foods (breakfast cereals, plant-based milks, tofu).


The National Institutes of Health (NIH) Office of Dietary Supplements[8] states that the two more common forms of calcium supplements are carbonate and citrate. Absorption is best when you take no more than 500 mg at a time. Side effects include gas, bloating and constipation. Avoid taking excessive amounts of calcium as there could be a link between too much calcium and an increased risk of both heart disease[9] and prostate cancer.

Vitamin D

Vitamin D[10] goes hand in hand with calcium when it comes to bone health. That’s because this “sunshine” vitamin helps the body to absorb calcium and fight off osteoporosis. But vitamin D is also integral for a healthy immune system[11], helping to fight off bacteria and viruses. In fact, with the ongoing COVID-19 pandemic[12], some studies have linked the incidence and severity of COVID-19 with vitamin D.

Vitamin D deficiency is fairly common, worldwide; one study estimates that 42% of the U.S. population is deficient. Your healthcare provider can order a blood test to determine how much vitamin D is in your blood. A level of 50 nanograms per milliliter (ng/ml) or higher is adequate for most people, but your provider should advise you as to your own goal.

How much do you need?

The recommended daily vitamin D intake[13] is 600 IU for adults 19 to 70 years, and 800 IU for those 71 and older.

Food sources

It can be a bit of a challenge getting enough vitamin D from food sources unless you turn to fortified foods, such as milk and some plant-based milks. Vitamin D is added to some yogurts, orange juice and cereals. Fatty fish, such as salmon and tuna, beef liver, cheese, egg yolks and mushrooms have small amounts of vitamin D.


Taking a vitamin D3 supplement is likely safe (although first discuss with your provider). The daily upper limit for vitamin D is 4000 IU. If you’re deficient, your provider will prescribe an amount to correct the deficiency.

Vitamin B12

Vitamin B12 is a nutrient needed to keep the nerves and blood cells healthy, and to make DNA. Vitamin B12 also protects against megaloblastic anemia. If you take metformin[14] to help you manage diabetes, there is a risk of developing a vitamin B12 deficiency[15]. In fact, studies show that between 6% to 30% of people using metformin long-term may be deficient in this vitamin[16]. One study showed that people with type 2 diabetes[17] taking more than 1,000 mg of metformin for four or more years had a high risk of developing a vitamin B12 deficiency. In 2017, the American Diabetes Association treatment guidelines began to recommend regular monitoring of vitamin B12 levels[18] in metformin users.

A lack of adequate vitamin B12 can cause tiredness, weakness, constipation, appetite loss, weight loss and megaloblastic anemia. Another common symptom is nerve damage; specifically, numbness and tingling in the hands and feet. These are also symptoms of peripheral neuropathy[19]. If you notice these symptoms and also take metformin, ask your provider to check your vitamin B12 level.

How much do you need?

Adults need 2.4 micrograms (mcg) daily[20].

Food sources

Poultry, fish, meat, eggs, dairy foods naturally contain vitamin B12; some breakfast cereals and nutritional yeasts are fortified with vitamin B12. Plant foods don’t contain vitamin B12 unless they’ve been fortified.


Vitamin B12 is found in most multivitamins, and supplements are available that contain either just vitamin B12 or vitamin B12 combined with other B vitamins. Prescription forms of vitamin B12 can be given as an injection or in the form of a nasal gel to treat a deficiency.

Vitamin C

Vitamin C (ascorbic acid) acts as an antioxidant, protecting cells from free radical damage; it also makes collagen, improves iron absorption from plant-based foods, and supports a healthy immune system. In terms of the COVID-19 pandemic, vitamin C has been of great interest: one study found that vitamin C supplementation decreased[21] the risk of death in severely ill COVID-19 patients. Intravenous administration of vitamin C reduced inflammation and respiratory distress syndrome, which are linked with COVID-19. Some researchers believe vitamin C is a highly promising treatment for COVID-19.

When it comes to diabetes, there could be some promise for vitamin C’s effect on blood sugars[22]. In a small study[23] published in the journal Diabetes, Obesity and Metabolism in 2019, a group of subjects given 500 mg of vitamin C twice daily had a 36% drop in blood sugar spikes after meals; they also had lower blood pressure levels compared to the group not given vitamin C.

Vitamin C may reduce the risk of heart disease, age-related macular degeneration and possibly some types of cancer. On the other hand, vitamin C supplements can interact with chemotherapy and radiation for cancer. In terms of the common cold, vitamin C may slightly reduce the duration and symptoms of a cold, but it doesn’t seem to lower the risk of getting a cold.

How much do you need?

The daily recommended amount[24] of vitamin C is 75 mg for women and 90 mg for men. Smokers need an additional 35 mg daily.

Food sources

Citrus fruits, red and green peppers, kiwifruit, strawberries, cantaloupe, broccoli, tomatoes and potatoes are excellent sources. Cooking and prolonged storage can reduce vitamin C levels.


Vitamin C is found in most multivitamins, but it’s also available as a single supplement or combined with other nutrients. The daily upper limit for vitamin C is 2,000 mg. Too much vitamin C can cause diarrhea, cramps, nausea, and in people with hemochromatosis, it may worsen iron overload and damage tissues.


Magnesium[25] is a mineral that regulates muscle and nerve function, helps with blood pressure management[26], and is needed to make protein, bone and DNA. It also helps to regulate blood sugar. Low levels of magnesium are linked with insulin resistance[27], a hallmark of type 2 diabetes. There’s also evidence from the Harvard T.H. Chan School of Public Health[28] that a high magnesium intake is linked with a lower risk of developing type 2 diabetes.

Too little magnesium over a long period of time, as well as certain medical conditions such as Crohn’s disease, type 2 diabetes and alcoholism can cause a deficiency, leading to nausea, vomiting, appetite loss, fatigue, muscle cramps and abnormal heart rhythm.

How much do you need?

Women need[29] between 310 and 320 mg daily; men need 400-420 mg daily.

Food sources

Green leafy vegetables, whole grains, legumes, nuts, seeds, milk, yogurt and fortified foods are sources of magnesium.


The magnesium in supplements comes in several forms, including magnesium aspartate, magnesium citrate, magnesium lactate and magnesium chloride. The daily upper limit for magnesium is 350 mg. Too much magnesium can cause diarrhea, cramping, irregular heartbeat and cardiac arrest. Magnesium found in food is not harmful and doesn’t need to be limited.

Want to learn more about eating well with diabetes? Read “Improving Your Recipes: One Step at a Time,”[30] “Top Tips for Healthier Eating”[31] and “Cooking With Herbs and Spices.”[32]

  1. vegetables:
  2. fruits:
  3. whole grains:
  4. complications of diabetes:
  5. sign up for our free newsletter:
  6. “bones.”:
  7. need 1,000 milligrams (mg) of calcium:
  8. National Institutes of Health (NIH) Office of Dietary Supplements:
  9. heart disease:
  10. Vitamin D:
  11. healthy immune system:
  12. COVID-19 pandemic:
  13. daily vitamin D intake:
  14. metformin:
  15. vitamin B12 deficiency:
  16. deficient in this vitamin:,deficiency%20due%20to%20metformin%20use.&text=In%20addition%2C%20some%20studies%20have,and%20dose%20of%20metformin%20use.
  17. type 2 diabetes:
  18. regular monitoring of vitamin B12 levels:
  19. peripheral neuropathy:
  20. 2.4 micrograms (mcg) daily:
  21. vitamin C supplementation decreased:
  22. blood sugars:
  23. small study:
  24. daily recommended amount:
  25. Magnesium:
  26. blood pressure management:
  27. insulin resistance:
  28. Harvard T.H. Chan School of Public Health:
  29. Women need:
  30. “Improving Your Recipes: One Step at a Time,”:
  31. “Top Tips for Healthier Eating”:
  32. “Cooking With Herbs and Spices.”:

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