Once considered important just for bone health, vitamin D is now considered perhaps the single most important nutrient impacting the entire body. Vitamin D interacts with over 30 different tissues in the body and affects 1,000-3,000 of your 30,000 genes. Getting sufficient vitamin D is important throughout your life. As you age and if you have dark skin or are overweight, you need even more.
Fast Fact: Only 1 in 10 Americans overall – whether children or adults – are getting sufficient vitamin D.
What it does: Your body can make vitamin D when your skin is exposed to sunlight, specifically UVB radiation. However, large portions of the US and global populations can’t get enough exposure year-round, and food is a poor secondary source of vitamin D, making supplementation the best bet for achieving even a baseline level for proper functioning of many of the body’s systems. Best known for its ability to stimulate calcium absorption, vitamin D also helps control calcium and phosphorus levels, which are necessary for strong bones and also muscle contraction, nerve conduction and the general function of all cells.
Interacting with more than 30 different tissues in the body, vitamin D has a demonstrated prevention and/or treatment role in autoimmune diseases, diabetes, infectious diseases, heart disease, certain cancers (for example, colorectal), respiratory conditions, depression, gastrointestinal diseases, obesity, pregnancy complications, and, as is well known, falls, fractures and dental health. Numerous studies have shown vitamin D has an impact on all-cause mortality. A meta-analysis of 42 randomized controlled trials found supplemental vitamin D significantly reduced mortality from all causes when taken for at least three years.
Where to Get It: By far, the best source is sun exposure (without sunscreen and not through a window) for at least 15 minutes a day and to as much of your body as possible. The next best way, and for many the only way, to get sufficient vitamin D is from a vitamin D3 supplement. It’s difficult to get enough vitamin D from your diet because only a few foods contain the form of vitamin D your body can use – mainly fatty fish, including herring or tuna canned in oil and cooked wild salmon, trout or mackerel. Vitamin D is present in much smaller amounts in fortified foods, milk and orange juice, as well as eggs (yolk), beef and butter.
Supplement Suggestions: Be sure to choose the D3 form. It’s 87% more effective than the D2 version. Krill oil capsules are a vitamin D-rich, sustainable option. Cod liver oil is another source. How much vitamin D you need varies depending on your age, weight, skin color, where you live and your individual dosage response. It’s also important to make sure you are getting enough vitamin K2 and to balance your magnesium and calcium intake. So, check your vitamin D levels, determine how much supplemental vitamin D is right for you, and be sure to take your vitamin D with some healthy fat or a fat-rich meal like dinner (remember, “D for dinner”) so your body can absorb it.
Need to Know: Because how much supplemental vitamin D each person needs varies widely, the only way to know if you are getting enough is to get your levels tested.