Vitamin D has been the “it” vitamin lately, and this time the benefits of this crucial nutrient live up to the hype. While you might know vitamin D is important for keeping our immune systems strong, this vitamin offers a multitude of other health benefits, from reducing risk of obesity to protecting our lung function. Otherwise known as the “sunshine vitamin,” vitamin D is critical to many of our bodies’ systems, yet with scant sunlight in the northern hemisphere for half of the year and few dietary sources of this vitamin, many of us may not be getting enough. Discover the myriad research-backed reasons you should fall in love with vitamin D.
1. Prevent Seasonal Flu: Researchers studied the anti-flu effects of vitamin D on 167 school children for four months. They concluded that vitamin D3 supplementation during winter can reduce the incidence of seasonal influenza, according to a study published in The American Journal of Clinical Nutrition.
2. Improve Muscle Function: Research shows a link between vitamin D, muscle function and recovery from daily activities (exercise, in particular). Low levels of vitamin D have been linked to muscle fatigue, while additional research on adolescent girls found that vitamin D supplementation can improve muscle strength.
3. Promote Bone Health: Vitamin D is the key to strong bones, as it promotes calcium absorption in the intestines (the primary location where nutrients are absorbed) and ensures proper bone mineralization, according to a 2011 study. Without vitamin D, our bodies can only absorb 10 to 15 percent of dietary calcium. When vitamin D is added, the percentage increases to 30 to 40 percent.
4. Reduce Heart Disease Risk: In a study of 1,739 people, researchers found that vitamin D deficiency is associated with an increased risk of heart disease, according to the journal Circulation.
5. Reduce Risk of Multiple Sclerosis: A study found a connection between blood levels of vitamin D and the risk of multiple sclerosis (MS), according to The Journal of the American Medical Association. Interestingly, researchers found no significant association between MS and vitamin D levels among black and Hispanic people tested, but found a significantly decreased risk of MS in white people with high levels of the vitamin. This is especially true among individuals younger than 20.
6. Protect Lung Function: Vitamin D deficiency is linked to a rapid decline in lung function among smokers, according to the American Journal of Respiratory and Critical Care Medicine. Researchers explored the relationship between vitamin D, smoking, lung function and lung decline in 626 men, and found that vitamin D had a protective effect on the lungs as well as the rate of lung function decline.
7. Suppress Appetite: Vitamin D may prevent overeating, as it has been shown to activate production of the appetite-suppressing hormone leptin, which signals to our brains that we’re full.
8. Reduce Risk of Obesity: There is also a correlation between obesity and vitamin D deficiency. Scientists found that women with the highest body mass index also had the lowest blood levels of vitamin D, in a study of 3,100 postmenopausal Scottish women over two years.
9. Reduce Risk of Diabetes: A study found a link between vitamin D deficiency and childhood obesity, as well as an increased risk of type 2 diabetes later in life, according to The Journal of Clinical Endocrinology & Metabolism. Researchers followed nearly 500 obese and nonobese children to determine the factors involved with diabetes in later years. They identified a connection between low vitamin D levels, insulin resistance and an increased likelihood of type 2 diabetes (non-insulin-dependent diabetes) later in life. They also found that vitamin D levels were lower in children suffering from obesity compared with nonobese children.
10. Improve Insulin Resistance: Insulin resistance is a condition in which the body’s cells aren’t responding properly to the hormone insulin, which is secreted by the pancreas in response to sugars and starches in the diet. Vitamin D can actually improve insulin sensitivity or secretion. In a study published in the British Journal of Nutrition, women who received a daily dose of 4,000 IU of vitamin D3 for six months saw improvements in insulin resistance.
11. Lower Blood Pressure: A study presented at a meeting of the European Society of Hypertension found that supplementing with vitamin D can reduce blood pressure in those with high blood pressure. An earlier study conducted by the American Heart Association found that a vitamin D deficiency in premenopausal women increases the risk of experiencing high blood pressure even many years later.
To Supplement or Not
The National Institutes of Health recommends getting vitamin D from three primary sources: moderate sunlight exposure, food and supplements. When we spend time in the sunlight (without sunscreen), our bodies manufacture vitamin D. During summer midday sun, we can manufacture enough vitamin D with 10 to 30 minutes of sun exposure (the darker your skin, the more time in the sun is required to produce vitamin D). However, north of Atlanta, low levels of UVB radiation (the type that activates our bodies to make vitamin D) get through the atmosphere from November through March, so we must rely on our diets and supplements. Tuna, salmon and mackerel are the primary food sources of vitamin D, but beef liver, mushrooms, fortified milk and egg yolks also contain some. Because it’s difficult to obtain all the vitamin D needed from sunlight or food, supplementation with D3 is recommended. Also known as cholecalciferol, vitamin D3 is the type that has been used in most studies showcasing the vitamin’s benefits. While some sources suggest 800 IU daily for adults, some health professionals recommend 2,000 IU daily. Vitamin D is available in a liquid form that’s readily absorbed under the tongue.
Test Your Health
We may understand that vitamin D is vital for good health, but 40 to 75 percent of Americans are still deficient. There is a new way to check whether you belong to this percentage: a test kit from the Vitamin D Council. Apply a few drops of your blood to the provided spot card, then ship your kit to the council’s partnering lab, Heartland Assays. Results will be uploaded to a secure webpage within one to two weeks. Order a kit for $50, or $180 for a family of four.