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NIFS Healthy Living Blog

Can Vitamin D Protect You Against COVID-19? The Latest Studies

GettyImages-1280576988Healthcare providers and scientists are all working diligently to find ways to prevent, treat, and cure COVID-19. Many of us are eager for answers and probably getting tired of not knowing what to believe. One of the hot topics floating around is about Vitamin D’s role in preventing COVID-19. Can Vitamin D really protect us against COVID-19 or at least lessen the effects? Let’s take a look.

The Role of Vitamin D

Vitamin D serves many purposes in the body, the most commonly known purpose being assisting calcium absorption and bone mineralization for good bone health. It is less well known that Vitamin D plays an essential role in immunologic function—keeping your immune system strong. Vitamin D inhibits both B cell and T cell (lymphocyte) proliferation/rapid increase, affects T cell maturation, and facilitates the induction of T regulatory cells. It also helps regulate monocytes production of inflammatory markers and inhibits dendritic cell (DC) differentiation and maturation. All of this leads to a decreased production of inflammatory markers and an increase in anti-inflammatory markers. In short, it has an anti-inflammatory role.

Vitamin D and COVID

Now that you understand the role of Vitamin D in immune support, let’s look at the link between that and COVID-19. When healthcare providers check your Vitamin D levels, they request a lab called 25-hydroxyvitamin d. This is the circulating Vitamin D in your body. Ideally, we want to see that number be at least 30 ng/dL. In theory, having enough circulating Vitamin D should reduce complications by preventing the “cytokine storm” that providers are seeing in response to COVID-19 infection. The cytokine storm is when the level of inflammatory proteins rapidly rises to dangerously high levels. It is what leads to complications such as ARDS, myocarditis, and acute renal and heart failure, especially in those elderly patients with previous cardiovascular comorbidity. Researchers have started requesting this lab from patients with COVID-19.

Study Shows Decreased Risk for Adverse Affects

One cross-sectional study of 235 individuals showed that patients with at least 30 ng/dL had a significantly decreased risk for adverse effects, such as hypoxia (low oxygen levels), death of individuals over 40, and unconsciousness. Serum C-reactive protein (an inflammatory marker) was lower and lymphocyte percentage was higher in Vitamin D–sufficient COVID-19 patients. In the study, 67.2% of the 235 COVID patients had Vitamin D levels less than 30 ng/dL. The study saw no significant difference in hospitalization duration, ICU admissions, Acute Respiratory Distress Syndrome (ARDS), and intubation between insufficient and adequate Vitamin D levels.

Similarly, a study showed Vitamin D levels were significantly lower in COVID patients with severe symptoms than those with mild symptoms or no COVID at all. Of the symptomatic patients, 54 were admitted to the ICU due to ARDS—all of whom had lower Vitamin D levels than the patients not needing the ICU. Sadly, 19 patients died, and again they found that these patients had lower Vitamin D levels than the ones who survived.

Another Study Finds Lower Levels of Vitamin D in Hospitalized Patients

A study of 216 COVID-19 patients and 197 population-based controls saw significantly lower levels of Vitamin D in the patients hospitalized due to COVID-19 than the controls (of similar age and sex), which lines up with the previous studies. On the contrary, they did not find a relationship between severity of infection and Vitamin D levels like the other studies found.

Study Finds People with Vitamin D Deficiency More Likely to Test Positive

Another study of 489 patients found that those with Vitamin D deficiency (<20 ng/dL) were 1.77 times more likely to test positive for COVID-19 than those with sufficient Vitamin D levels. The study above by Hernandez et al supports this finding, showing that 82.2% of COVID-19 cases were deficient in Vitamin D compared to the population-based controls, where only 47.2% were deficient (which is significant).

Correlation Is Not Causation

Something to note: These studies are observational studies. Thus, we cannot determine a cause-and-effect relationship between vitamin D deficiency and COVID-19 infection outcomes. Correlation is not synonymous with causation. So, while these results are important and useful, we must be careful to not go as far as saying, “Vitamin D can protect me from COVID-19 or lessen the impact if I get sick with COVID-19.”

Further research is being conducted since we do have strong observational support that suggests low Vitamin D levels may favor respiratory dysfunction and even death in those with COVID-19. Several Randomized Control Trials are in process. Many are trialing high-dose Vitamin D in those with COVID-19, such as the registered study by University Hospital in Angers (France). One has already concluded, but it was small with only 50 hospitalized patients being given a high dose of Vitamin D (calcifediol) and 26 not given a high dose of Vitamin D. Only 1 of the 50 high-dosed patients needed ICU treatment, whereas 13 of the 26 not given Vitamin D needed ICU treatment. 

GettyImages-1147455976Vitamin D Recommendations

Let me be real clear: You do not need to start taking a megadose of Vitamin D! Doing so can actually lead to toxic effects because it is a fat-soluble vitamin. The goal is to prevent deficiency to help keep your immune system strong.

I do suggest reflecting on your Vitamin D intake and exposure. Do you get out in the sun 10–30 minutes several times weekly? Sun exposure is less common in the winter, which hints at why more people are Vitamin D deficient in the winter months. When the sun’s UV rays hit our skin, Vitamin D3 (cholecalciferol) synthesis can occur. Do you eat Vitamin D–rich sources? If not, start to add some foods that are rich in Vitamin D. This will help you reach the RDA of 600 IU for young adults under 70 years old and 800 IU for adults older than 70 years old.

Here are some Vitamin D–rich foods:

  • Trout, rainbow, cooked (3 oz = 648 IU)
  • Pink salmon, cooked (3 oz = 444 IU)
  • Halibut, Atlantic or Pacific, cooked (3 oz = 196 IU)
  • Portobello mushrooms (1/2 cup = 316 IU)
  • Canned tuna (3 oz = 228 IU)
  • Milk, whole, 1%, 2%, and nonfat (1 cup = 115–128 IU)
  • Yogurt, various types and flavors (8 oz = 80–120 IU)
  • Soy milk (1 cup = 116 IU)
  • Orange juice, fortified (1 cup = 100 IU)
  • Eggs (1 large = 44 IU)

If getting your RDA by eating these foods is not realistic for you, I would suggest a Vitamin D3 (cholecalciferol) supplement to help increase your intake. A Registered Dietitian can help you adapt your nutrition regimen to meet Vitamin D requirements.

Finally, speak with your healthcare provider. They can always request that your 25-hydroxyvitamin d (circulating Vitamin D in your body) lab be checked. If you’re found to be deficient, you may require larger doses for treatment.

The Bottom Line

We do have strong observational support that suggests low Vitamin D levels may favor respiratory dysfunction and even death in those with COVID-19. However, we simply do not have enough strong data to conclude that Vitamin D sufficiency can treat or prevent COVID-19 infection until Randomized Control Trials are complete.

In the meantime, the best thing to do is continue to stay healthy (or improve your health) and keep your immune systems strong, which includes eating enough Vitamin D or having adequate Vitamin D exposure.

As always, please reach out to a NIFS Registered Dietitian for any nutrition support you need.

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This blog was written by Sabrina Goshen, NIFS Registered Dietitian. To learn more about the NIFS bloggers, click here.

Topics: nutrition immunity vitamins vitamin D registered dietitian covid-19 pandemic

Taking Dietary Supplements Safely: Advice from a NIFS Dietitian

GettyImages-505820296Dietary supplement usage is reaching an all-time high. The 2019 Consumer Survey on Dietary Supplements revealed that 77% of Americans consume supplements. This is a dramatic increase from the 53% reported by the NHANES in 2010. Americans are spending $38.8 billion a year on supplements, with more than 85,000 supplements on the market. Reasons for consumption are widespread, ranging from athletes hoping to boost performance to people who need more Vitamin D for bone health.

With the rise in supplement usage, it is important to be an informed consumer. While there are numerous reasons for this, one of the biggest is that supplements are loosely regulated by the FDA, meaning labels may not display what is truly in the supplement. Also, claims marketed about the benefits of a supplement may be false because companies are not required to obtain authorization from the FDA prior to making such nutritional support claims.

How can you know whether what you’re taking is safe and effective? Let’s dive in!

What Is a "Dietary Supplement?"

According to the Dietary Supplement Health and Education Act of 1994 (DSHEA), a dietary supplement means “a product (other than tobacco) intended to supplement the diet that bears or contains one or more of the following ingredients:

  • Vitamin
  • Mineral
  • Herb or other botanical
  • Amino acid
  • A dietary supplement used by man to supplement the diet by increasing dietary intake
  • A concentrate, metabolite, constituent, extract, or combination of any ingredient described in the above.”

Are Dietary Supplements Regulated? Can Supplements Be Trusted?

Technically, yes, supplements are regulated by the FDA under the DSHEA. However, there are loopholes to consider:

  1. The FDA does not inspect products before they are sold, nor do they require registration unless the supplement contains a new ingredient not yet on the market.
  2. The only formulation standard is the Current Good Manufacturing Practice (GMP); however, 2013 report by the FDA revealed that 70% of inspected manufacturers were in violation of GMPs. Not all products even get inspected after being on the market. The FDA states the manufacturer is responsible for ensuring safety and quality, but clearly some manufacturers are doing a poor job, and the FDA is only catching some.
  3. Nutrition supplements may not claim to diagnose, cure, prevent, or treat diseases. Sure enough, some manufacturers have managed to ignore this. A 2003 study found that 81% of 338 herbal supplement retail websites made one or more health claims, and 55% claimed to diagnose, cure, prevent, or treat specific diseases.

What Can You Do to Be Safe When Taking Supplements?

Blind trust in supplements is unwarranted; however, there are steps you can take to ensure your safety while taking them.

  • Check the label for a stamp indicating third-party verification. Independent third parties are hired by manufacturers to thoroughly test products, ensuring accuracy of ingredients, potency, and amounts; absence of toxic compounds; and production in compliance with FDA GMPs. Credible third parties include NSF International and US Pharmacopeia (USP).
  • Athletes: look for the NSF Certified for Sport stamp. The USA Doping Agency (USADA) has recognized this program as best suited to assist athletes in choosing supplements that do not contain banned substances for sports.
  • Download the NSF International App. It shows which products are NSF approved—right at your fingertips anytime, anywhere.
  • Check out the Dietary Supplement Fact Sheets published by the National Institutes of Health: Office of Dietary Supplements. This government agency has quick fact sheets about a variety of dietary supplements, including vitamins, minerals, probiotics, botanicals and herbs, and more.

Speak with a Registered Dietitian for supplement guidance and which supplements may (or may not) be right for you. NIFS Registered Dietitians are available to help you!

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This blog was written by Sabrina Goshen, NIFS Registered Dietitian. To learn more about the NIFS bloggers, click here.

Topics: NIFS nutrition supplements dietitian drugs sports nutrition dietary supplements registered dietitian

Intermittent Fasting for Weight Loss: Does It Work?

GettyImages-1059024598Losing weight is regularly ranked as one people's top New Year’s resolution. That’s probably why everyone and their mother is on a diet of some sort. One that is trending, and probably one you have heard about, is intermittent fasting. Intermittent fasting has been around for quite some time but has gained popularity over the years. The question is: is intermittent fasting really effective for weight loss? Yes and no. Confused? Let’s dig in.

What Is Intermittent Fasting?

Intermittent fasting (IF) is an eating pattern that focuses on meal timing by cycling fasting and nonfasting periods. The eating pattern specifies timing of intake versus quality of food. Three popular methods of IF include the following:

  • The 16/8 method
  • Eat–Stop–Eat or Alternate-day fasting
  • The 5:2 diet

The 16/8 is the most common and entails 16 hours of fasting followed by an 8-hour eating window.

The Evidence of the Effects of Fasting

Several studies have explored the effect of intermittent fasting on weight loss. A 2019 study observed 332 overweight and obese adults. They compared weight loss and weight maintenance across three groups; week-on-week-off caloric restriction (a common IF method), continuous caloric restriction (the traditional daily calorie deficit), and the 5:2 IF method. Mean weight and fat loss at 12 months were similar across the three groups, and all groups saw significant weight loss.

Another study supported these results. Alternate-day fasting did produce significant weight loss, as did the control group who followed the traditional daily caloric deficit. A systematic review also showed that intermittent fasting (ranging from 3–12 months) produced weight loss as long as participants maintained a caloric deficit.

A common theme among all these weight-loss studies is that all groups, both intermittent fasting groups and traditional calorie-restrictive groups, maintained some type of caloric deficit, meaning they were burning more calories than they were eating (calories in < calories out/burned). So, it wasn’t intermittent fasting that produced the weight loss; it was the caloric deficit. Granted, intermittent fasting was a way some could sustain the caloric deficit. However, others reported more pronounced feelings of hunger when following IF, and some studies had significantly higher dropout rates in the IF groups due to people struggling to follow the method.

The Bottom Line

Weight loss requires a caloric deficit to work successfully. The method in which one obtains this caloric deficit and maintains the caloric deficit will vary. One method, such as IF, may work for one person and not work for another. No weight-loss intervention, IF included, is a one-size-fits-all.

If you are one who naturally fasts (for example, you don’t eat breakfast) or one who needs structure, intermittent fasting may be a solid approach to meeting your caloric deficit. If you are one who binges after a fast or struggles to make it through a fast, intermittent fasting is not for you. Stick with the traditional caloric-deficit approach.

Finding the Weight-Loss Method That Works for You

The biggest thing that goes wrong, at least for weight loss, is failing to make a sustainable plan—one that produces lifestyle changes. If the method for weight loss you are trying is not working for you and is something you can’t stick with, it’s time for a change. If you’re struggling to find your sustainable lifestyle approach, consider seeing a Registered Dietitian.

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This blog was written by Sabrina Goshen, NIFS Registered Dietitian. To learn more about the NIFS bloggers, click here.

Topics: nutrition weight loss calories registered dietitian intermittent fasting fasting