News Alert: Vitamin D and Immune Health
If you want to understand how important vitamin D is to immune health, consider two facts. First, there are vitamin D receptors on almost every immune cell in the body. Second, there are no less than 15 human genes involved in the action of vitamin D on the immune system. Not surprisingly, there’s been a flurry of interest in vitamin D’s role in supporting respiratory health over the past year.
A study published last June in the scientific journal Medicine in Drug Discoveries found a correlation between where Americans live and their respiratory health status. Specifically, the study found the further south you live, the better respiratory outcome you have after an immune challenge. The researchers speculated that people living in climates where it’s easier to absorb vitamin D from sunlight were better protected than those who didn’t see the sun as much.
Another recent study, published last September in the journal Aging Clinical and Experimental Research, studied the sunshine vitamin’s effect on cytokines. These immune system proteins normally help contain an immune challenge. But sometimes, they can overreact, making the immune system go a bit haywire. This study concluded vitamin D may help regulate cytokine production, benefitting respiratory health.
These findings reinforce previous research. A 2020 study on 191,000 individuals by leading vitamin D researcher Dr. Michael Holick found that being deficient in vitamin D increased the risk of falling under the weather by 54.5 percent.
Interestingly, many experts consider 30–39.9 ng/mL within the normal range for vitamin D. Typically, 20 ng/mL is the cutoff for deficiency. (By that measurement, 42 percent of Americans are deficient. Some even argue that number should be lowered to 12.5 ng/mL. However, the Endocrine Society recommended in 2011 maintaining between 40–60 ng/mL to ensure sufficiency.
To achieve those levels, you’d likely have to consume more than the Recommended Daily Allowance (RDA) of 10–800 mcg (400–800 IU) for vitamin D. In a recent article published in the journal Nutrients, the authors recommended 50 mcg (2,000 IU) of vitamin D daily.
Top vitamin D foods
You can get some vitamin D from your diet. Fatty fish (think salmon), mushrooms, egg yolks, and liver all contain small amounts of vitamin D. One egg yolk offers up about 1 mcg (40 IU) of vitamin D – but since the RDA is 15 mcg (600 IU), sunshine and supplements are still your best bet.
Signs and symptoms of vitamin D deficiency
Vitamin D deficiency symptoms in adults are often subtle and easy to miss. These can include mood changes, muscle weakness, occasional aches or cramps, and fatigue. A more obvious sign is weak immune function.
Vitamin D benefits
Vitamin D3 helps your body absorb calcium, and the two nutrients work together to help you maintain healthy bones and teeth. Vitamin D3 also helps your muscles, nerves, and immune system work properly.
Moreover, vitamin D3 supports neurons to promote healthy cognitive function. This nutrient is in a class of its own, with receptors everywhere in the body—including the muscles and heart—a hint that it plays a role in many more physical functions than we know.
What’s the difference between vitamin D and vitamin D3?
Vitamin D supplements come in two forms, natural D3 (cholecalciferol) and synthetic D2 (ergocalciferol). Vitamin D3 is more easily absorbed than D2 and lasts longer in the body.
Look for a liquid or softgel vitamin D supplement (because vitamin D is absorbed best in the presence of fat), and double check that you’re getting D3 and not D2. For people following a plant-based diet, rather than take D2, seek out vegan D3 sourced from lichens.
*Article adapted from Natural Factors blog