How Sunlight Exposure Can Help Beat Metabolic Syndrome

Most of us can remember being taught from an early age that sunlight exposure is how we get an essential vitamin or good health -- Vitamin D. Vitamin D is sometimes referred to as the “sunshine vitamin.” When our skin is exposed to sunlight, the sun’s ultraviolet B (UVB) rays penetrate cholesterol in our skin cells, which provides the energy for Vitamin D synthesis to occur.  Deficiencies of vitamin D have been scientifically linked to a group of health conditions related to metabolic syndrome, which begs the question: What role can sunlight exposure play in protecting us from metabolic syndrome?

What is Metabolic Syndrome?

Metabolic syndrome is the name for a group of five risk factors that could increase your chances of developing conditions like heart disease, diabetes, and strokes. The five conditions that make up the metabolic syndrome profile, according to the National Heart, Lung, and Blood Institute are as follows:

1. A large waistline due to belly fat. Excess fat in the abdominal area presents a greater risk factor than fat accumulation in other parts of the body, such as hips and thighs.
2. Elevated triglyceride levels. Triglycerides are a type of fat located in your blood.
3. Decreased HDL cholesterol level. HDL is often referred to as the "good" cholesterol because it helps remove cholesterol from arteries. Low levels of HDL cholesterol raise your risk of heart disease.
4. Hypertension or high blood pressure. If your blood pressure rises and stays high over time, it causes the heart to work harder, which can damage your heart and contribute to the build-up of plaque.
5. Increased blood sugar levels. Moderately high blood sugar could be an early sign of diabetes.

You can have any one of these conditions by itself, but they tend to cluster together. An official diagnosis of metabolic syndrome requires the presence of at least three of the five risk factors. Metabolic syndrome is linked closely to obesity and a low level of physical activity.

Metabolic Syndrome and Vitamin D

There's a connection between vitamin D deficiency and metabolic syndrome. The precise cause-and-effect is still being researched, but the correlation is unequivocal. Here are some examples: 

• In Qatar there is nearly year-round sunlight, yet vitamin D deficiency has been increasing along with metabolic syndrome. Previous research discovered that up to 64% of the Qatari population was vitamin D deficient.
• Yet another study discovered that vitamin D deficiency was associated with a higher prevalence of metabolic syndrome in postmenopausal women. Women who were deficient in vitamin D had higher triglyceride levels and lower HDL (good cholesterol) levels than those who had normal levels of vitamin D. Vitamin D is also essential to bone formation and calcium assimilation, along with cardiovascular health.

Sunlight Exposure vs Supplementation

Researchers estimate that 40% of American adults are vitamin D deficient, so it’s time to consider getting more sunlight and perhaps supplementing with vitamin D. Sunlight is the best source of vitamin D. Noontime is the most ideal time of day to be in the sun for maximum vitamin D assimilation. 30 minutes of midday summer sun exposure is roughly the equivalent to consuming 10,000–20,000 IU of vitamin D.           

However, If we’re unable to spend sufficient time out in the sun each day, our best means of ensuring that we maintain healthy levels of vitamin D is through supplementation. The minimum recommended daily dosage of vitamin D is 600 IU (15 mcg). However, most vitamin D supplements in the marketplace contain much higher levels, from 5000 IU to as much as 50,000 IU per serving. If you’re looking to supplement with vitamin D, talk to your doctor to learn which dose is right for you.

Ultimately, if you’re trying to boost your vitamin D levels and lessen your chances of potential health risks, get outside as often as you can and enjoy nature’s gifts, especially our life-giving star, the sun. Your health just might thank you for it.

References:

1. Al-Dabhani K, Tsilidis KK, Murphy N, et al. Prevalence of vitamin D deficiency and association with metabolic syndrome in a Qatari population. Nutr Diabetes. 2017;7(4):e263. Published 2017 Apr 10. doi:10.1038/nutd.2017.14
2. Metabolic Syndrome. National Heart Lung and Blood Institute website. https://www.nhlbi.nih.gov/health-topics/metabolic-syndrome
3. Moukayed M, Grant WB. Linking the metabolic syndrome and obesity with vitamin D status: risks and opportunities for improving cardiometabolic health and well-being. Diabetes Metab Syndr Obes. 2019;12:1437–1447. Published 2019 Aug 16. doi:10.2147/DMSO.S176933
4. Parva NR, Tadepalli S, Singh P, et al. Prevalence of Vitamin D Deficiency and Associated Risk Factors in the US Population (2011-2012). Cureus. 2018;10(6):e2741. Published 2018 Jun 5. doi:10.7759/cureus.2741
5. Schmitt EB, Nahas-Neto J, Bueloni-Dias F, Poloni PF, Orsatti CL, Petri Nahas EA. Vitamin D deficiency is associated with metabolic syndrome in postmenopausal women. Maturitas. 2018;107:97–102. doi:10.1016/j.maturitas.2017.10.011