Vitamin D, Sunlight, and Metabolic Syndrome

Vitamin D boosts mood, fights depression, and helps prevent health conditions related to metabolic syndrome.

J.D. Vines

J.D. Vines

J.D. Vines

Vines is a holistic health educator and herbalist, with an extensive history researching nutritional supplements. Vines holds degrees in both metaphysics and mysticism from Denver University.


- Vitamin D is the ‘sunshine vitamin’. When we’re out in the sunlight, and our skin becomes exposed to the rays of the sun, the sun’s ultraviolet rays (UVB) activate cholesterol in our skin cells. This activation provides the energy necessary for vitamin D synthesis to take place. 

- Nearly half of all U.S. adults are deficient in vitamin D which can lead to depression, anxiety, and metabolic syndrome.

 - For those who eat a plant-based diet, and who don’t get out in the sun enough, the only sources for plant-based vitamin D are mushrooms and supplementing our diets with vitamin D-3. 

With vitamin D being so easily accessible just by being outdoors in sunlight, it would be logical to assume that everyone has plenty. However, researchers estimate that 40% of American adults are deficient in vitamin D [1]. This deficiency results from a combination of factors which include:

Sunlight exposure supports life and helps prevent health conditions related to metabolic syndrome.

1. Most people work or attend school indoors. 

2. Recreation and exercise often take place in gyms and other indoor environments. 

3. Some climates are not conducive to outdoor activity during periods of extreme cold or heat. 

4. Our modern obsession over viewing screens (phones, T.V.’s, laptops, iPads) is mostly an indoor phenomenon. 

5. We just don’t get outside enough to enjoy the natural environment. 

6. Current pandemic conditions require us to stay indoors.

Vitamin D is an essential vitamin and plays an important role in our health and well-being. It has numerous benefits for us, and may: 

- help fight diseases like multiple sclerosis [2]. 

- help prevent heart disease [3]. 

- help us prevent getting the flu [4] 

- help enhance mood and ward off depression [5] 

- help us lose weight, especially belly fat [6]

Vitamin D is also vital to bone formation and the assimilation of calcium. According to one research team, “Vitamin D deficiency is widespread” [7].

Sunlight Exposure and Vitamin D Supplementation

Sunlight is, of course, our best source of vitamin D. Midday is the best time of day to be in the sun in order to maximize vitamin D assimilation [8]. One study determined that 30 minutes of noontime summer sun exposure provided the same amount of vitamin D as consuming 10,000–20,000 IU of vitamin D supplements [9,10].

Plant-Based Sources of Vitamin D-3:

About the only type of natural food which contains vitamin D, with the exception of fish and eggs, is mushrooms. So, if you eat a plant-based diet, and you don’t spend sufficient time outdoors in the sunlight, you need to stock up on plenty of mushrooms.

Mushrooms are an excellent plant-based source of vitamin D.

Otherwise, you will need to supplement your diet with vitamin D. The minimum recommended daily serving is 15-20 mcg (600-800 IU).

Vitamin D and Metabolic Syndrome:

Researchers have discovered a link between vitamin D deficiency and a group of health conditions commonly referred to as metabolic syndrome. What role can sunlight and vitamin D play in protecting us from developing metabolic syndrome? 

Metabolic syndrome is a group of five risk factors that increase a person’s chances for developing heart disease, diabetes, and stroke. Metabolic refers to the physiological processes which sustain the body’s normal functions. Heart disease, in this context, refers specifically to the build-up of plaque within the arteries. Over time this plaque hardens, reducing the flow of blood. This impaired blood flow reduces the amount of blood available to our tissues and organs, and can result in damage to the heart, high blood pressure, and can cause heart attacks. 

There are five conditions, or risk factors that make up the metabolic syndrome profile [11];

Vitamin D-3 from Verb to boost mood, ease anxiety, fight depression, and boost metabolism.

Belly FatExcess fat in the abdominal area presents a greater risk factor for developing metabolic syndrome than fat which has accumulated in other areas of the body, such as thighs and hips. 

Elevated Triglyceride Levels:Triglycerides are a type of fat which are found in your blood. 

Low HDL Cholesterol: HDL cholesterol is the ‘good cholesterol’, helping to clear cholesterol from arteries. Low levels of HDL raise your risk for heart disease. 

High Blood PressureIf your blood pressure remains too high over time, your heart has to work harder, which can damage the heart and contribute to the build-up of plaque. 

High Blood Sugar: Even moderately high blood sugar levels could be an early sign for the onset of type II diabetes.It is, of course, possible to have any one of these conditions by itself. However, they tend to cluster together. A medical diagnosis for metabolic syndrome requires the presence of at least three of the five [12]. Metabolic syndrome is often accompanied by a lack of physical activity and obesity. 

Vitamin D Deficiency

Scientists have found an unequivocal correlation between vitamin D deficiency and metabolic syndrome [13]. One of the obvious connections here is that people who are vitamin D deficient are also more likely to lead a sedentary lifestyle, since they don’t get outside enough.

Scientists believe that exposure to sunlight can help prevent metabolic syndrome, especially the accumulation of belly fat and obesity. One animal study concluded: 

“In our animal studies, ongoing exposure to low dose ultraviolet radiation (UVR found in sunlight) reduced weight gain and the development of signs of cardiometabolic dysfunction in mice fed a high fat diet. These observations suggest that regular exposure to safe levels of sunlight could be an effective means of reducing the burden of obesity [14].”

Sunlight helps reduce the risk of developing metabolic syndrome.

Another researcher framed the vitamin D/obesity issue within a global health perspective:

“The global death toll from noncommunicable diseases is exceptionally high, reported to cause 71% of global deaths worldwide…Vitamin D3 can positively reverse many of these adverse effects… We propose that everyone in general and obese patients in particular consider raising vitamin D levels through UVB (sunlight) exposure and/or supplemental vitamin D3 intake to reduce cardiometabolic and metastatic disease and increase longevity [15].”

Sun Exposure and Recreation:

Get outside and enjoy nature, especially our life-giving star, the sun. None of us get outside enough. If you have a dog, and you’re wondering what he’s thinking or what he’d like to say to you, he’s probably barking, “hey c’mon, let’s go outside, let’s go outside”. We should probably listen more to our pets…oh wait, they don’t speak English. 

Vegans and vegetarians should supplement with vitamin D-3 to boost mood and metabolism