Vitamin D is a fat-soluble vitamin that plays a role in many important body functions. It is sometimes called the “sunshine vitamin” since it is produced in our skin in response to sunlight.
It is best known for working with calcium in your body to help build and maintain strong bones. Vitamin D is also involved in regulating the immune system and cells, where it may help prevent cancer.
There are two forms of vitamin D: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Some research suggests that cholecalciferol is better at raising levels of vitamin D in the blood.
VITAMIN D HEALTH BENEFITS
When you think of strong bones, calcium often comes to mind. Calcium is the major player when it comes to bone health and increasing bone mineral density, but don’t overlook the importance of vitamin D.
Previous research has shown that vitamin D is a strong stimulator of calcium deposition in bones, making them stronger and healthier. If you’re not getting enough vitamin D, your body begins to slow or stop depositing calcium into bones, eventually drawing calcium out from your bones back into the bloodstream. Over time, this constant cycle of deposit and withdrawal makes bones weak and at high risk for fractures.
PROTECTION FROM CARDIOVASCULAR DISEASE
The classic function of vitamin D is to increase absorption of calcium to maintain proper bone health, but did you know it has a protective effect on your heart? Recent evidence has demonstrated that individuals deficient in vitamin D are at an increased risk for high blood pressure, heart disease, sudden cardiac death, or heart failure.
Although the exact mechanisms are unclear at this time, it appears that vitamin D can help lower blood pressure, improve vascular compliance (how elastic your arteries are), and improve glycemic control. Save your heart by supplementing with the D!
DECREASED RISK OF TYPE 2 DIABETES
Type 2 diabetes can lead to some devastating long-term complications, including nerve damage, heart disease, eye damage and vision loss, and kidney failure. Recent evidence suggests that vitamin D may play a significant role in reducing the risk for type 2 diabetes—especially in those who are at an increased risk for this deadly disease.
Several observational studies have shown improvements in beta cell function, insulin sensitivity, and whole-body inflammation with higher levels of vitamin D.
REDUCED RISK OF CANCER
Research suggests that sufficient vitamin D levels in adulthood may significantly reduce the risk for many types of cancer, including colon, breast, ovarian, and prostate.
Vitamin D is one of the most potent inhibitors of cancer-cell growth, and reduces the risk of cancer by increasing calcium absorption and cell differentiation, while reducing metastasis (the spread of cancer from one organ to another).
PROTECTION FROM AUTOIMMUNE DISEASES AND INFECTIONS
Vitamin D is a potent immune modulator, making it very important for the prevention of autoimmune diseases, like MS and inflammatory bowel disease. It also helps you fight infections of all kinds. A study done in Japan, for example, showed that schoolchildren taking 1,200 units of vitamin D per day during the winter time reduced their risk of getting influenza A infection by about 40 percent.
HOW TO GET YOUR DAILY VITAMIN D
A study found that the life expectancy for women who avoided the sun decreased by 0.6 to 2.1 years compared to women with the highest sun exposure.One of the easiest, and not to mention free, ways to be on your way to your daily dose of Vitamin D is to just get out in the sun!
When your skin is exposed to UVB radiation from sunlight, previtamin D is formed before being shuttled into the bloodstream. From there, it is quickly moved to the liver and converted to vitamin D.
Production in the skin is maximized in roughly 10-15 minutes, depending mainly on skin pigment (darker skin colors may require a little more time out in the sun).
Fatty fish can be a good source of vitamin D. Common options include salmon, trout, mackerel, tuna, and eel.
Canned tuna fish
Fresh fish aren’t the only way to boost your vitamin D intake; you can get vitamin D from a can, too.
Canned tuna fish and canned sardines both contain vitamin D, and are usually less expensive than fresh fish.
Almost all types of cow’s milk in the U.S. are fortified with vitamin D, but ice cream and cheese are not.
Eggs are a convenient way to get vitamin D. They’re popular in many breakfast, lunch, dinner, and dessert recipes.
Since the vitamin D in an egg comes from its yolk, it’s important to use the whole egg—not just the whites. One yolk will give you about 40 IUs, but don’t try to get your daily vitamin D just from eggs.
Although it might not be the most appealing source due to the cholesterol it contains, a 3.5-ounce serving of cooked beef liver contains about 50 IUs of vitamin D—and several other nutrients. You’ll also be getting vitamin A, iron, and protein.
Cod liver oil
While its name might suggest a less-than-savory flavor, cod liver oil is often flavored with mint or citrus, or comes in capsule form.
SIGNS OF VITAMIN D DEFICIENCY
It’s often difficult to tell if newborns are deficient, but a sweaty forehead is one of the first noticeable symptoms, Holick says. The same rings true for adults, so if you’re “glowing” while your activity level remains steady, your temperature is close to 98.6° and you’re in a moderate temperature environment, you may want to consider a vitamin D test.
2. Noticeable—and unexpected—weakness
Muscle strength isn’t just a matter of pumping iron. While having a vitamin D deficiency can leave you feeling overly exhausted, even when you’re able to get enough shut-eye, proper vitamin D intake helps you maintain power in every fiber of your being, whether you’re young or old. Promising news: Within just six months of supplementation, D-linked muscle weakness can be eliminated, according to a Western Journal of Medicine study.
3. Broken bones
You stop building bone mass around age 30, and a lack of vitamin D can speed up or worsen osteoporosis symptoms, according to research published in the American Journal of Clinical Nutrition. Fortification, first introduced around 1930, almost eradicated the weak bone condition rickets. According to this research, the optimal intake of vitamin D is provided by sun exposure, food, and supplements.
4. Chronic pain
Some people may experience subtle aches and pains in the bones, known as “osteomalacia. Those who are diagnosed with arthritis or fibromyalgia may actually be shy of enough D, as a deficiency can cause joints and muscles to ache, too. If your discomfort lasts for several weeks, ask your doctor if a vitamin D deficiency could be the cause—and if your treatment program should include the vitamin.
5. A down-in-the-dumps mood
A depression diagnosisis often actually linked to a shortage of vitamin D. While the jury is still out about why, the Vitamin D Council says that the mineral may work in the same brain areas—and impact the same hormones, like serotonin—as those that affect mood.