Worldwide interest in the health protective benefits of Vitamin D has increased exponentially since the start of the COVID-19 pandemic. Low Vitamin D status has a strong association with serious, chronic health conditions including infectious disease while high Vitamin D promotes good gut health and a strong immune system.
As this is emerging research, it’s easy to feel confused by conflicting scientific opinions. Here are the answers to many of the key questions surrounding Vitamin D, including if Vitamin D can improve gut health.
Is Vitamin D Good for More than Healthy Bones?
Vitamin D is a fat-soluble vitamin essential to maintaining calcium balance to support bone health, muscle contraction, and cardiovascular function.
Over the past 20 years, particularly during the last few years, low serum Vitamin D level (the level of Vitamin D circulating in blood) has been associated with many chronic health conditions, among them:
- Ricketts
- Bone loss leading to osteopenia or osteoporosis
- Depression
- Diabetes
- Cancer, including breast, colon, and ovarian
- Multiple Sclerosis
- Hypertension
- Metabolic syndrome
- Autoimmune conditions
- Infectious disease, including respiratory tract viral infection and coronavirus
Can Vitamin D impact gut health?
While Vitamin D includes many health benefits, its impact on gut health can sometimes be overlooked. A 2019 study investigated the effects of Vitamin D on the intestinal barrier function. In this study, getting enough Vitamin D was linked to healthier microbiome composition and improved immune functions.
Vitamin D’s impact on gut health can improve sleep and reduce pain as well. A study from 2016 suggested that Vitamin D impacted the intestinal microbiome. Vitamin D deficiency reduces B vitamin in the gut. In contrast, three months or more with the proper amount of Vitamin D results in better gut health, improved sleep, and reduced pain.
But Vitamin D has other contributions to intestinal health. It has been known to decrease the risk of Crohn’s disease, untreated celiac disease, and pancreatic enzyme insufficiency. A groundbreaking 1996 study from Harvard even found men with the highest Vitamin D intake were 50% less likely to develop colon cancer, a finding which has been supported and found through other trials over the last 25 years.
Can Vitamin D Help Prevent Viral Infection?
The research is not conclusive nor final…but it is compelling. Scientists have seen in both human and animal studies that Vitamin D plays an important role in immune system regulation, including how the immune system mounts a defense against viruses that invade the body. Recent studies suggest that people who are low in Vitamin D have greater risk for, and worse outcomes from, respiratory infection. Vitamin D seems to up-regulate or kick into high gear the immune response around certain types of viruses. It also is being studied for its role in treatment of viral infections.
What is a ‘Normal’ Level for Vitamin D?
Optimal serum levels for Vitamin D are a matter of debate. Different medical organizations recommend different threshold levels. For example, the Institutes of Medicine report that people with less than 25 ng/mL are deficient and 50-75 ng/mL is sufficient. The Endocrine Society, on the other hand, agrees with the 25 ng/mL for deficiency but states that levels should be higher than 75 ng/mL. Most holistic practitioners strive for a circulating level > 50 ng/mL.
When you hear “low Vitamin D,” that can mean severe deficiency – a value so low that a person can develop a disease like Ricketts or suffer from bone loss. But it can also mean insufficient, which are levels that are not necessarily as high as they need to be for optimal function but not low enough to develop a disease.
Who Is Low in Vitamin D and Why?
Since 2008, research interest in Vitamin D expanded from a focus on the implications of simple deficiency to looking at the role of Vitamin D in the prevention of health problems. Research has revealed important findings including a detailed picture of who is most lacking in Vitamin D:
- Affects both the developing world and industrialized world.
- Rates are higher among women than men.
- Affects 50 -70 % of the European adult population
- Is 20% or higher for non-Hispanic whites, and up to 70% for non-Hispanic Blacks.
Even in countries with plentiful sunlight year-round, levels can be below recommended levels. An example is India, a country with a prevalence rate of 50-94% Vitamin D deficiency.
Over the years, studies on Vitamin D have focused on deficiency, rather than optimal levels for optimal function. This has changed as the association between insufficient Vitamin D and chronic health conditions continues to appear in more varied and large-scale clinical studies.
Can I Boost My Vitamin D Level, Naturally?
To boost Vitamin D level naturally, experts recommend a minimum of 15-minutes, up to 30-minutes, of daily sunlight exposure without applying sunscreen. Your skin produces more Vitamin D when you spend time in the sun during the middle of the day at the time the sun is at its highest point in the sky. While this type of sun exposure can elevate Vitamin D levels, it is not a permanent solution for maintaining an optimal level of Vitamin D throughout the year. Other factors such as weather, geography, elevation, and personal health concerns come into play.
How much Vitamin D should I take?
The answer to this question varies by age, stage of life (infancy, childhood, teens, adult years, older adult years), sun exposure, skin tone, and by health status. The National Institutes of Health has not adjusted Vitamin D recommendations in a very long time. Holistic health practitioners, and a growing number of conventional medicine physicians, recommend much higher doses than the 600 iu daily that is currently suggested. At a minimum, 2,000 iu and up to 5,000 iu daily is what is suggested.
However, the ideal level for you should be discussed with your holistic practitioner who will identify your need based on health history and lifestyle factors. Together you can decide how much sun exposure to get and/or how much and what kind of Vitamin D supplementation is needed. Since Vitamin D can build up to toxic levels if you take too much, it is very important to follow your doctor’s guidance.
Can I take too much Vitamin D?
Yes, you can take too much Vitamin D and the effects of this are significant. Vitamin D toxicity can cause blood calcium to spike, resulting in a condition called hypercalcemia. This can cause dizziness, fatigue, palpitations, confusion, nausea, vomiting and painful GI tract symptoms. Although D toxicity is rare, it is something to be careful about. Always let your healthcare providers know the type and amount of nutritional supplements you are taking.
Vitamin D has garnered a great deal of attention during these past two years. As research continues and the science evolves, we will understand more about the role Vitamin D plays in the immune response, gut health, and protecting us from serious illness. To ensure you’re getting enough Vitamin D, spend time in direct sunlight and talk to your health practitioner about supplements or how to add foods high in Vitamin D to your diet.