High blood levels of vitamin D counteract atherosclerosis and type 2 diabetes

Coronary occlusion is the leading cause of death worldwide. Type 2 diabetes is spreading like a bushfire and this disease is characterized by atherosclerosis and early death. Diet and lifestyle are of vital importance and the same goes for vitamin D. According to a new American study that is published in Nutrients, people whose blood levels of vitamin D are above the official threshold levels have fewer biomarkers of cardiovascular disease, type 2 diabetes, and metabolic syndrome.

Vitamin D is known for its role in bone and muscle health but all cells in the body have vitamin D receptors (VDR). The nutrient helps control around 10 percent of cellular genes and a host of biochemical processes, which means vitamin D is also important for normal blood sugar and a healthy cardiovascular system. Both type 2 diabetes and atherosclerosis are characterized by chronic inflammation and the reason why vitamin D has such a wide scope of effects is that it also regulates the production of proinflammatory cytokines in the immune system. Cytokines are also used as a marker of disease.

Higher blood levels of vitamin D make a huge difference

Blood levels of vitamin D are categorized as actual deficiency (below 30 nmol/L), insufficiency (30-50 nmol/L) and sufficiency (over 50 nmol/L), but according to the new American study and several earlier studies, the vitamin D level should ideally be higher than 75 nmol/L.
The recent US study includes 13,462 American adults. The scientists collected data from a larger study called National Health and Nutrition Examination Survey (NHANES) and compared the different participants’ blood levels of vitamin D in relation to metabolic syndrome, biomarkers for cardiovascular disease, and cardiovascular fitness (CVF), which is a measure of the cardiovascular system’s (lungs, heart, circulatory system) ability to deliver oxygenated blood to the muscles during physical activity. Cardiovascular fitness is also known as as physical fitness or VO­­­­2 max.
The researchers found that participants with vitamin D levels of 75 nmol/L or higher had a significantly lower rate of metabolic syndrome and type 2 diabetes compared with those participants whose vitamin D levels were below 30 nmol/L.
Participants with the highest vitamin D levels in their blood had smaller waist circumference, and blood analyses revealed that they also had lower levels of triglycerides and homocysteine, a higher level of (beneficial) HDL cholesterol and fewer cases of insulin resistance. In general, it appeared that they had better carbohydrate metabolism and a lower risk of developing diabetes. Participants with the highest levels of vitamin D also had better cardiovascular fitness (CVF) and were more fit.
The scientists concluded that having blood levels of vitamin D of 75 nmol/L or higher is associated with a lower risk of diabetes and cardiovascular disease in American adults.

Vitamin D and its positive effect on blood sugar, cholesterol and cardiovascular health

Insulin resistance is the most common cause of type 2 diabetes. This insidious condition typically takes years to develop and is often a result of too much dietary carbohydrate and lack of vitamin D. Ingested carbohydrates are converted into blood sugar (glucose). The pancreas then produces insulin, the hormone that transports glucose into the cells. In the case of insulin resistance, the body does not respond properly to its own insulin, which means the cells do not get enough glucose for their energy turnover. The unused carbohydrates that pile up in the bloodstream are then converted into fat deposits, typically around the vital organs (visceral fat), often leading to increased waist circumference.

1. Vitamin D has several functions according to other studies. It is involved in:
2. The pancreatic insulin production and insulin release
3. Insulin sensitivity and glucose uptake in the liver, muscles, brain, and other tissues
4. Regulation of the cholesterol balance
5. Regulation of the white immune cells and proinflammatory cytokines. Vitamin D regulates low-grade inflammation that is typically seen with obesity, insulin resistance, and type 2 diabetes
6. Influences the endothelial cells in blood vessels and the heart

Endogenous vitamin D production and supplementation

You can easily synthesize 30-100 micrograms of vitamin D on a hot summer’s day, depending on how long you stay in the sun and how much skin you expose. But you need a vitamin D supplement if don’t get enough sun during the summer, and most certainly in the winter where the sun is not powerful enough to enable vitamin D synthesis
Normal vitamin pills contain too little vitamin D to optimize your vitamin D levels in your blood but there are supplements on the market that contain 20-80 micrograms. The actual need for vitamin D depends on things like sun exposure, age, skin type, BMI, and chronic diseases like diabetes. Vitamin D is lipid-soluble so your body absorb and utilizes it best if you take the nutrient in oil-filled capsules.

References:

Ganji V et al. Serum Vitamin D Concentration ≥75 nmol/L Is related to Decreased Cardiometabolic and Inflammatory Biomarkers, Metabolic Syndrome, and Diabetes; an Increased Cardiorespiratory Fitness in US Adults. Nutrients, 2020 Mar 10

Scott LaFee. Vitamin D Deficiency Linked to Greater Risk of Diabetes. UC San Diego Health. April 2018

Plasma 25-hydroxyvitamin concentration and risk of type 2 diabetes and pre-diabetes. 12-year cohort study. PLoS One 2018

Sisley SR et al. Hypothalamic Vitamin D Improves Glucose Homeostasis and Reduces Weight. Diabetes 2016

Iowa State University: New promise for diabetics with vitamin D-deficiency. ScienceDaily. 2016

Pernille Lund. Sådan får du styr på dit blodsukker og din vægt. Ny Videnskab 2013