Can Vitamin D Really Control Insulin and Help in Reducing Diabetes Risk?
Vitamin D goes by many names – wonder vitamin, miracle worker, sunshine nutrient. What makes it unique is its ability to convert itself into calcitriol. It is a hormone that helps regulate phosphorus and calcium levels in the body. This vitamin has also the ability to absorb calcium from calcium-rich foods and use it to strengthen bones in the body.
The link between vitamin D levels and glucose metabolism has been very active area of research. Many studies now associate low levels of vitamin D in the body with higher chances of diabetes and increased insulin resistance. This vitamin sufficiency in turn is thought to provide protection against type 2 diabetes.
So What’s Really The Connection?
When our body stops making enough insulin or becomes resistant to it Type 2 diabetes develops, resulting in an impaired glucose metabolism. Vitamin D is supposed to have a predominant role in producing insulin, controlling glucose levels and reducing resistance to insulin. Therefore, a deficiency in this vitamin can induce insulin resistance and increase chances of type 2 diabetes.
Another connection between this Vitamin and diabetes is attributed to the role of calcium. Vitamin D regulates calcium, which in turn controls the release of insulin. If there are fluctuations in the levels of calcium in the body, there is less insulin regulation, leading to diabetes. Vitamin D indirectly controls insulin by regulating calcium.
According to Clemente-Postigo et al., people with low levels of vitamin D are more prone to type 2 diabetes, prediabetes, and metabolic syndrome than people with normal vitamin D levels, irrespective of their weight. Another study by Dutta et al. showed that in prediabetic individuals with vitamin deficiency, a combination of calcium supplements and vitamin D, diet, and exercise could lower the chances of type 2 diabetes. According to the researchers, the risk of diabetes dropped by 8% for every unit increase in vitamin D levels achieved through supplementation. Large-scale interventionist studies will help make this connection clearer.
This vitamin has also an impact on diabetics. According to an observational study by Joergersen et al., type 1 diabetes participants with very low levels were more likely to die (of varied causes) than those with sufficient levels of this vitamin.There is no link between these vitamin levels and the development of diabetes-induced kidney or eye disease. The researchers noted the need for further investigations to assess whether vitamin supplements would benefit people with diabetes.
Vitamin D, Be My Sunshine
Very few natural foods contain vitamin D. Fatty fish (tuna, mackerel, salmon), fish liver, beef liver, egg yolks and cheese are some sources. One natural and easily accessible source of this vitamin is sunlight. When bare skin is exposed to sunlight, it quickly synthesizes vitamin D in the body. Approximately 5–30 minutes of sun exposure between 10 am and 3 pm at least twice a week to the face, legs, arms, or back without sunscreen leads to sufficient vitamin D content in the body. The amount of this vitamin absorbed from the sun depends on the color of the skin, time of the day, and the amount of skin exposed.
In dietary supplements and fortified foods, this vitamin is available as cholecalciferol and ergocalciferol. Some natural supplements include mushrooms grown in UV light, canned tuna, and cereals, fortified milk, and orange juice. The Food and Nutrition Board recommends the following daily intake of vitamin D: infants, 400 UI/day; children, 600 UI/day; adults, 600 UI/day; and seniors, 800 UI/day.
Don’t Go Overboard
Excess intake of this vitamin can be harmful, causing vitamin toxicity. This happens when you take 40,000 UI/day of supplements for a long time. Consuming large amounts of vitamin D leads to the production of a chemical called 25(OH)D by the liver. High levels of this chemical can in turn lead to an increase in calcium levels in the blood, resulting in hypercalcemia.