Every time you turn around there is yet another news story about the importance of vitamin D. The “sunshine vitamin” has been shown to be beneficial for bone health, immune health, fertility, and more.
It’s time for a Q&A – dive into the top nine questions about vitamin D and health to build your knowledge and understand why this nutrient is so important.
1. What is vitamin D?
Vitamin D is a fat-soluble vitamin that functions to maintain healthy blood levels of calcium and phosphorus. Vitamin D enhances the absorption of calcium, thus helping to build and maintain strong bones.
2. Ergocalciferol vs. cholecalciferol?
There are two main types of vitamin D available in food and dietary supplements: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).
Ergocalciferol (vitamin D2) is the plant form of vitamin D and typically comes from mushrooms and yeast. Most prescription vitamin D products contain vitamin D2.
Cholecalciferol (vitamin D3) is the type of vitamin D your body produces after exposure to sunlight. There aren’t a lot of foods that naturally contain vitamin D3, but fatty fish like salmon and herring are great sources. Most supplements source their vitamin D3 from lanolin, but as plant-based supplements become more popular, some products include vitamin D3 from lichen.
Research suggests that vitamin D3 is better than vitamin D2 at raising blood levels of vitamin D, so vitamin D3 is usually the preferred supplemental form.
3. Can you get vitamin D from the sun?
Vitamin D is sometimes called the “sunshine vitamin” — and for good reason. With enough sun exposure, your body can make all the vitamin D you need.
However, if you’re not exposed to enough sunlight, you may not produce enough vitamin D. The same is true if you have a hard time metabolizing vitamin D or have reduced liver or kidney function. The amount of vitamin D produced in the body from sun exposure can also vary greatly depending on your age, geographical location, time of day, smog, and use of sunscreen.
As you get older, your skin becomes less efficient at synthesizing vitamin D from sunlight. Older adults are also more likely to spend time indoors, which can affect vitamin D production. Location is also very important in determining the amount of vitamin D you can produce from the sun. In most of the United States, you cannot make vitamin D from sunlight for four months of the year. If you live in the Northern U.S. or Canada, it may be difficult in as many as seven months.
Moreover, using sunscreen reduces the amount of vitamin D produced through sun exposure. Experts still recommend using sunscreen to protect your skin and overall health from the sun, but keep in mind that sunscreen with an SPF of 8 or greater will block 90% of the rays that you need to produce vitamin D.
4. Can you get vitamin D from food?
It is difficult to get enough vitamin D from your diet alone because vitamin D occurs naturally in very few foods. Fatty fish (such as salmon), liver, and egg yolks naturally contain some vitamin D. Breakfast cereals and milk are often fortified with vitamin D. The process of fortification adds vitamin D to food or beverages that may not contain it naturally. Drinking a quart of fortified milk each day provides you with about 10 mcg (400 IU) of vitamin D.
5. How do you know if you’re getting enough vitamin D?
The optimal vitamin D blood level is a long-debated topic, but most experts agree that you should aim for at least 30 ng/ml. If you’re curious or concerned about your vitamin D levels, be sure to discuss with your healthcare provider – they can order a simple blood test to determine your vitamin D level.
6. How much vitamin D do you need?
Experts don’t completely agree on how much vitamin D you need each day, either. The current Recommended Dietary Allowance (RDA) for vitamin D is 15-20 mcg (600-800 IU) per day, depending on age, and the upper limit for daily intake is 100 mcg (4,000 IU).
Vitamin D experts, however, consider the RDA to be conservative and typically recommend higher doses for most adults. Research suggests that doses between 50 mcg (2,000 IU) and 100 mcg (4,000 IU) are both safe and effective at maintaining healthy vitamin D levels. Individuals with higher weights, those that take medications that affect vitamin D metabolism, or those that have difficulty absorbing vitamin D may need even higher amounts of vitamin D each day. Make sure you talk with your healthcare provider to determine how much vitamin D you need each day.
7. Why is vitamin D important for bone health?
Most people focus on calcium for bone health, but vitamin D deserves some credit, too. Sure, calcium is essential to build and maintain strong bones, but vitamin D helps your body effectively absorb calcium. So, they work together, and you really need both for optimal bone health.
As you age, you gradually lose bone mass. It’s a normal process, but getting adequate amounts of key bone health nutrients, like calcium and vitamin D, can help maintain your bone strength and support an active lifestyle for years to come.
8. Aside from bone health, does vitamin D have any other health benefits?
Shady Grove Fertility highlights that healthy vitamin D levels can help support fertility and are linked to higher pregnancy rates in certain women trying to conceive. Healthy vitamin D levels are also essential to support healthy pregnancy outcomes, immune health, and hormonal health.
9. Can you get too much vitamin D?
Although vitamin D is an invaluable nutrient, too much of a good thing isn’t always a good thing. Vitamin D is fat-soluble, which means that it’s hard for your body to get rid of it if you get too much. The upper limit for vitamin D is 100 mcg (4,000 IU). Excess vitamin D intake can cause elevated levels of calcium in your blood, which can lead to other issues.
While it is difficult to get too much vitamin D from food, supplements make it easier. Vitamin D doses up to 100 mcg (4,000 IU) per day are generally safe. Higher doses may be recommended for certain individuals, but should only be taken under the supervision of a healthcare provider. If you take (or are interested in taking) a vitamin D supplement, talk with your doctor to determine the appropriate dose for you.
Should you be worried about sunlight? Not really. The body is very efficient at limiting the amount of vitamin D produced by the body. Therefore, you do not have to worry about getting too much vitamin D from sunlight. But if you’re spending more time in the sun, be sure to protect your skin with sunscreen.
Vitamin D is a key player in your overall health. With roles in bone health, immune function, fertility, and pregnancy, it’s important to make sure you get enough of this vital nutrient. Choose vitamin D-rich foods when you can, spend some time in the sun (safely), and consider a high-quality vitamin D supplement to fill in the gaps. Make sure any vitamin D product you choose is independently tested and certified – this is your best guarantee that what’s in the bottle matches what’s on the label.