Vitamin D and Covid-19: Do You Need Supplements?
Have you seen the headlines:
"Vitamin D Deficiency May Boost COVID-19 Risk"
Have you wondered if you should be taking Vitamin D supplements?
Before you run to the store, read this article where I succinctly answer the following questions:
- What's the role of vitamin D?
- What does the Covid-19 and vitamin D research studies report?
- Should I take supplements?
- How to check your vitamin D levels
- How much vitamin D do I need?
- What foods contain vitamin D?
- How does sunlight increase vitamin D levels?
- What's the case for vitamin D supplements?
- What vitamin D supplements are best?
- How can I assess the quality of the supplements?
- Do medications interfere with vitamin D?
What's the Role of Vitamin D?
We often think of vitamin D in terms of bone growth and keeping bones healthy and strong. That's because vitamin D promotes calcium absorption in the gut and ensures normal bone mineralization.
But, vitamin D is used by nearly every cell within the body for so many other functions including glucose metabolism. Nerves need vitamin D to carry messages between the brain and every part of the body. Muscles need the vitamin to move.
Extremely low levels of vitamin D can lead to fatigue. Plus, the immune system requires vitamin D to help fight off infection from bacteria and viruses.
Vitamin D and Covid-19
Several studies have recently shown that people who are deficient in vitamin D may be at higher risk of contracting the novel coronavirus than those with sufficient levels.
In one study, individuals with untreated vitamin D deficiency were nearly twice as likely to test positive for COVID-19 relative to their peers with adequate vitamin D levels.
The researchers say that the findings also raise the possibility that treatment for vitamin D deficiency may lower the risk of COVID-19.
Another study found participants positive for COVID-19 were 50% more likely to have low vs normal vitamin D levels.
So, Should I Take Vitamin D Supplements?
Keep in mind that these studies suggest that people who are deficient in vitamin D may be at a higher risk of contracting covid-19.
It is not suggesting that people with normal levels of vitamin D need to take supplements.
High levels of vitamin D in the body has risks, too, including problems with heart rhythms and kidney damage.
Yet, deficiency isn't as rare as you might think. One recent study found 40% of participants were deficient.
First, Check Vitamin D Levels
Before deciding that you need more vitamin D, ask your doctor or primary medical professional to do a simple blood test to check to check serum concentration vitamin D in the form of 25(OH)D.
That's because supplementation is not recommended if your serum levels are already adequate. More is not better.
Labs may differ but generally, values between 30-50 ng/mL (75-125 nmol/L) are recommended.
- < 30 nmol/L (<12 ng/mL) = at risk of vitamin D deficiency
- 30 to 50 nmol/L (12 to <20 ng/mL) = potentially at risk of inadequacy. Though the Endocrine Society stated that concentrations of more than 75 nmol/L (30 ng/mL) is necessary.
- > 125 nmol/L (>50 ng/mL) = can be associated with adverse effects
How Much Vitamin D Do I Need?
The Recommended Dietary Allowance for vitamin D is 600 IU per day for most people. The recommendation for babies and older adults is shown below:
- Birth to 12 months = 400 IU
- 1 - 70 years = 600 IU
- Adults 71 years and older = 800 IU
Ok, so now that you know how much vitamin D you need, are you getting that much in your diet? Read on...
What Foods Contain Vitamin D?
Vitamin D is fat-soluble vitamin that's naturally found in only a few foods rich in fat including fatty fish such as salmon, tuna, and mackerel. These contain around 600 IU per 3-ounce serving.
But chances are you're not eating fatty fish every day. Many people don't even like fish.
Most of our vitamin intake is through fortified milk. Almost all of the U.S. milk supply is fortified with 400 IU of vitamin D per quart (so just 100 IU per cup), and so are many of the plant-based alternatives such as soy milk, almond milk, and oat milk. Most other milk products (such as ice cream and cheese) are typically NOT fortified.
Some brands of orange juice, yogurt, and margarines MAY also contain added vitamin D. And, you may also notice labeling on SOME mushrooms that have been exposed to UV light to boost their vitamin D content.
As you can see, most people find it difficult to get enough vitamin D through foods alone.
How Does Sunlight Increase Vitamin D?
Vitamin D is also available from sunlight. It's produced in the body when ultraviolet B (UVB) rays from sunlight strike uncovered skin and trigger vitamin D synthesis.
Time of day, length of day, cloud cover, and smog can play a role in how much vitamin D is produced. In addition:
- People with dark skin are less able to produce vitamin D from sunlight.
- Older people also have difficulties
- UVB radiation does not penetrate glass (in cars or building)
- Sunscreens with an SPF of 8 or more appear to block vitamin D-producing UV rays
- People tend to have lower levels during the winter months or when living in latitudes with less sunlight
Some experts suggest that approximately 5–30 minutes of sun exposure, particularly between 10 a.m. and 4 p.m., at least twice a week to the face, arms, hands, and legs without sunscreen usually leads to sufficient vitamin D synthesis.
On the other hand, UV exposure is the most preventable cause of skin cancer, so getting more sun might not be the solution. Sunscreen with a sun protection factor (SPF) of 15 or higher is recommended when exposed to the sun.
The Case for Vitamin D Supplements
You don't need to supplement your diet if your serum levels are already adequate. Remember, more is not better. High serum levels can cause serious issues.
If your medical professional finds out that your serum vitamin D levels are deficient, s/he will likely write a prescription. The standard treatment is 50,000 IU vitamin D to be taken weekly for 8 weeks, followed by a recheck of your serum levels.
Another round might be prescribed if the values are still low.
If your serum vitamin D levels rise back into the normal range, realize they will fall again if you go back to your previous lifestyle. Unless you can significantly increase your intake of vitamin D (more sunlight is not recommended because of the risk of skin cancer), you'll likely need a supplement.
What Vitamin D Supplements are Recommended?
Dietary supplements can contain vitamins D2 or D3 (check the label); both forms are well-absorbed in the gut. Because vitamin D is a fat-soluble vitamin, more is absorbed when its consumed with fat.
And both raise serum 25(OH)D levels. The evidence suggests that vitamin D3 increases serum 25(OH)D levels to a greater extent and maintains these higher levels longer than vitamin D2.
Vitamin D2 is manufactured using UV irradiation of ergosterol in yeast - and preferred by many following a vegan lifestyle. Vitamin D3 may be produced with irradiation of vegan-friendly products or animal products such as lanolin.
Selecting a Quality Supplement
The U.S. Food and Drug Administration (FDA) is the federal agency that oversees medicines and supplements. Yet the regulations for supplements are less stringent than those for either over-the-counter or prescription medications.
While medicines must be approved by the FDA before they can be sold or marketed, supplements do not require this approval.
Supplement companies are responsible for having evidence that their products are safe. FDA does not determine whether dietary supplements are effective before they are marketed.
As long as the product does not contain a “new dietary ingredient” (one introduced since October 15, 1994), the company does not have to provide this safety evidence to the FDA before the product is marketed.
The FDA has established good manufacturing practices that companies must follow to help ensure they put the right ingredient in its purest form (no contamination) in the right strength identity. The FDA periodically inspects facilities that manufacture supplements, but not the supplements.
Dietary supplement labels may include certain types of health-related claims. Manufacturers are permitted to say, for example, that a supplement promotes health or supports a body function (like immunity or heart health). But, keep in mind, this should not be inferred that YOU need this. For example, vitamin D helps to build strong bones...but that doesn't mean YOU need more.
These claims must be followed by the words, “This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.”
If the FDA finds a dietary supplement to be unsafe, it may remove the product from the marketplace or ask the manufacturer to voluntarily recall the product.
The Federal Trade Commission monitors product advertising to make sure that information about a supplement product to be truthful and not misleading.
The federal government can take legal action against companies and websites that sell dietary supplements when the companies make false or deceptive statements about their products, if they promote them as treatments or cures for diseases, or if their products are unsafe.
Several independent organizations offer quality testing and allow products that pass these tests to display a seal of quality assurance that indicates the product was properly manufactured, contains the ingredients listed on the label, and does not contain harmful levels of contaminants. They don't guarantee that a product is safe or effective.
Organizations that offer quality testing include:*
- NSF International (look for the NSF logo on the label)
- U.S. Pharmacopeia (look for the USP logo on the label)
Do Medications Interact with Vitamin D Synthesis?
Yes. If you're taking any of these medications, be sure to discuss vitamin D levels with your healthcare provider:
- Orlistat (Xenical and alli), along with a reduced-fat diet, can reduce the absorption of vitamin D from food and supplements
- Statin medications reduce cholesterol synthesis, which then lead to a reduction in vitamin D synthesis. In addition, high intakes of vitamin D, especially from supplements, might reduce the potency of some of the statins such as Lipitor, Mevacor, and Zocor.
- Corticosteroid medications, such as prednisone are often prescribed to reduce inflammation. These medications can reduce calcium absorption and impair vitamin D metabolism
- Thiazide diuretics (such as Hygroton, Lozol, and Microzide) decrease urinary calcium excretion. The combination of these diuretics with vitamin D supplements might lead to hypercalcemia (high serum calcium) in certain individuals.
The bottom line is that maintaining normal serum levels of vitamin D are recommended for many health reasons - including possibly reducing your risk for Covid-19. But, high serum levels of 25(OH) D can have negative consequences so it's recommended not to take supplements without checking with your primary care physician and getting your serum levels checked - and then rechecked again periodically. Your levels tend to fall during times when sun exposure is less.
Want to learn more about vitamin D and your energy and health? Watch my four-minute whiteboard video or listen to this episode of my Energize Your Life podcast.
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