One large meta-analysis published by Harvard University in 2017, for example, found that taking vitamin D may help prevent serious respiratory infections, such as influenza, especially in those who are deficient in the vitamin.ĭr. The BMJ authors write that high doses - up to 10,000 IUs/day - of the nutrient are being recommended online, but the authors “strongly caution against doses higher than the upper limit 4,000 IUs/day.”Īnd although a major a link between COVID-19 and vitamin D has not been drawn, there is still research that suggests taking the supplement may help with immune function. The National Institutes of Health’s Office of Dietary Supplements recommends 600 IUs a day of vitamin D for most people, 400 IUs for those under 2 and 800 IUs for those over 70. But in the U.S., current recommendations are just a fraction of that. The Mayo Clinic notes that “taking 60,000 international units (IU) of vitamin D a day for several months” has been shown to cause toxicity. “Vitamin D is not the best for everyone, but if you have normal kidney function then your body should be able to process and clear it through the urine.” “It’s pretty low-risk, especially if you have normal kidney function,” says Patel. Kavita Patel said it’s important to be aware of the potential dangers, but adds that overdosing on vitamin D is extremely uncommon.
In an earlier interview on the topic with Yahoo Life, medical contributor Dr. Vitamin D toxicity - officially referred to by the Mayo Clinic as hypervitaminosis D - is rare, but can cause “a buildup of calcium in your blood (hypercalcemia), which can cause nausea and vomiting, weakness and frequent urination.” The condition can prove most dangerous for those with liver or kidney problems, which Adalja says may lead to a “lower threshold for overdose.” “These calls are without support from pertinent studies in humans at this time, but rather based on speculations about presumed mechanisms.” “The continued spread of the novel SARS-CoV-2 virus, and the disease COVID-19 that is caused by SARS-CoV-2, has led to calls for widespread high-dose vitamin D supplementation,” the authors write. But the report warns individuals not to simply start taking those mega doses. The paper comes on the heels of a study suggesting that vitamin D deficiency may be linked to higher rates of mortality with COVID-19. and eating foods that provide vitamin D is particularly important for those self-isolating with limited exposure to sunlight.” Foods high in vitamin D include fatty fish (such as salmon and tuna), portobello mushrooms, fortified milk and yogurt and eggs.īut high doses of the vitamin - which the authors refer to as “mega doses” can be extremely dangerous. “Many people have low blood levels of vitamin D, especially in winter or if confined indoors, because summer sunshine is the main source of vitamin D for most people,” the authors write. conclude that while vitamin D is “essential for good health” (especially for bones and muscles) and may bolster the immune system, it can also be dangerous in high doses.
In a paper published in the British Medical Journal this month, 21 experts from the U.K., Ireland and the U.S. A new paper from the British Medical Journal suggests that vitamin D is an "essential" element of immune function, but that high doses of it can be dangerous.