With cases of COVID-19 remaining steady in parts of the country, and experts warning that there could be a second wave later this year, folks are understandably looking for answers about how to protect themselves and others. If you've heard murmurings that vitamin D may help prevent or treat the disease caused by SARS-CoV-2, don't rush out to stock up on supplements just yet. Here's what we know about the possible connection, and how you can ensure you're getting the vitamin D your body needs, in the safest way possible.
How Does Vitamin D Affect the Immune System?
"Vitamin D is crucial for proper immune function," Habib Sadeghi, DO, founder of Be Hive of Healing Integrative Medical Center in Agoura Hills, CA, and author of The Clarity Cleanse, told POPSUGAR. "As an immunomodulator, it's central to regulating the body's immune response by interacting with immune cells that produce vitamin D-activating enzymes. In this way, vitamin D ensures the immune system remains in balance and reacts appropriately to various threats."
What Happens When You Don't Have Enough Vitamin D?
While healthy levels of vitamin D can do wonders for your body's defense system, not having enough of this immune-boosting micronutrient can put you in dangerous territory. According to Dr. Sadeghi, a large portion of the population is believed to be D deficient, with people of color being at even greater risk. That's obviously not good news.
"People with low vitamin D levels have been found to have a higher susceptibility of chronic infections and autoimmune disease," Dr. Sadeghi explained.
He also noted the connection between vitamin D and lack of sunlight, which has been shown to lead to a number of increased illnesses. "People who live in places with fewer daylight hours are more susceptible to certain kinds of cancer, such as colon cancer, Hodgkin's lymphoma, ovarian cancer, pancreatic cancer, and prostate cancer. This is likely due to a lack of vitamin D," Dr. Sadeghi said.
Can Vitamin D Help Protect Against COVID-19?
Scientists have reported that there is some circumstantial evidence that a lack of vitamin D may contribute to the spread of the novel coronavirus and poorer outcomes in patients with COVID-19. An analysis by researchers at Northwestern University suggests that vitamin D may play a role in COVID-19 mortality rates, with D-deficient patients being "twice as likely to experience severe complications, including death." (Still, the authors said that more research is needed.)
While experts suspect that vitamin D's role in regulating the inflammatory response may help explain any connection, Dr. Sadeghi noted that vitamin D deficiency has also been found to contribute to acute respiratory distress syndrome (ARDS). The study he referenced concluded that a lack of vitamin D may lead to the development of ARDS and advised doctors to help vitamin D-deficient patients correct that deficit. A 2017 meta-analysis published in BMJ also showed a benefit from vitamin D in treating respiratory disease. "Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall," the authors reported.
So, while vitamin D is far from a COVID-19 cure — you'll still want to take the necessary precautions to prevent the spread, and isolate if you do get sick — it might be in your best interest to ensure you're getting an adequate amount, particularly during a respiratory virus pandemic.
How Can I Get More Vitamin D?
First, take advantage of those eased stay-at-home restrictions and be sure you get a bit of natural sunlight. Even 30 minutes can make a significant difference in your body's production of the sunshine vitamin. "Don't overdo it, because too much sun damages DNA in skin cells and actually suppresses immunity," Dr. Sadeghi said.
Vitamin D is also present in many foods. Dr. Sadeghi recommends wild caught salmon, herring, sardines, cod liver oil, low-sugar yogurt, cheese, and egg yolks. There'a also a ton of vitamin D in canned tuna.
If you're concerned you may not be getting adequate vitamin D from the environment or your diet, "always get your current levels checked by your doctor first before starting supplementation," he advised. If the results warrant it, your doctor may suggest that you take a vitamin D3 supplement to stay healthy and safe, whether you're exposed to COVID-19 or not.
POPSUGAR aims to give you the most accurate and up-to-date information about the coronavirus, but details and recommendations about this pandemic may have changed since publication. For the latest information on COVID-19, please check out resources from the WHO, CDC, and local public health departments.