Are Vitamin D Supplements Beneficial?
Vitamin D supplements are an effective way to help many people increase and maintain adequate levels of vitamin D. Because food sources of vitamin D are limited, and—in many parts of the world—it’s not possible to make adequate vitamin D in your body from sun exposure, a large majority of the population can benefit from vitamin D supplements. If you have a known deficiency, supplements are beneficial.
However, the following groups of people may find them especially helpful:
- Older adults. Older adults are at higher risk for vitamin D deficiency because the ability of skin to synthesize vitamin D declines as we age. They may also spend less time outdoors.
- People with darker skin. Skin with more pigment (color) produces less vitamin D than lighter skin. People of African American descent are known to be at higher risk of vitamin D deficiency than those with white skin.
- People who have difficulty absorbing fat. If you have a medical condition that lessens your ability to absorb fat such as liver disease, crohn’s disease, ulcerative colitis, and cystic fibrosis, or have had your gallbladder removed, you may be at higher risk for deficiency.
- People who have had bariatric surgery. Bariatric surgery reduces your ability to absorb all nutrients, including vitamin D. In addition, it’s been shown that fat cells can hold onto vitamin D and not release it into the bloodstream effectively, leading to deficiency. The Endocrine Society recommends a dose of 3,000 IU or more daily for anyone who has had bariatric surgery.
- People who have a high body fat percentage. People in larger bodies, particularly those with high fat mass, are at higher risk for vitamin D deficiency because fat cells may not efficiently release vitamin D into the bloodstream.
- Pregnant people. Vitamin D plays an essential role in the skeletal development of a baby, and may play a role in other pregnancy outcomes. It’s essential that pregnant people maintain adequate levels of vitamin D.
- People trying to conceive. Research suggests that adequate vitamin D levels may play a role in fertility, and vitamin D deficiency or insufficiency may lower your chance of conceiving.
- Post menopausal women. Post menopausal women are at higher risk for osteoporosis, and getting adequate vitamin D can help maintain bone density.
- People with osteoporosis. It’s recommended that people with osteoporosis take 800 IU of vitamin D daily to support bone density and reduce risk of fractures.
- People with PCOS. It’s estimated that up to 85 percent of people with PCOS are vitamin D deficient. A supplement may help with symptoms and risk of other conditions.
- Breastfed babies. Breast milk contains very little vitamin D, and babies who are exclusively breastfed should take a supplement. Some research indicates that when breastfeeding mothers take high doses (6,400 IU) of vitamin D, there may be adequate levels of vitamin D in breastmilk. Speak with your healthcare provider to determine the best approach for you and your baby.
- People with chronic kidney disease or liver disease. These illnesses can affect your body’s ability to convert vitamin D into a usable form.
Who May Not Benefit From Vitamin D Supplements
Vitamin D supplements are considered safe for most people. However, the following people may not benefit from a supplement, or the risks may outweigh the benefits.
- People with adequate vitamin D levels. If you are able to maintain blood vitamin D levels of 30nmol/L throughout the year via food and sunshine, there is little to no benefit to supplements. And excessive vitamin D may lead to harmful side effects.
- People with high blood calcium levels. Caroline Thomason, RD, CDCES advises those with high blood calcium to talk with their doctors before they take a Vitamin D supplement. This is because vitamin D enhances calcium absorption, which can lead to excessive calcium, explains Sharon Puello MA, RD, CDN, CDCES.
- People prone to kidney stones. Vitamin D supplements may elevate risk for kidney stones because they increase absorption of calcium. More research is needed to clarify the relationship between vitamin D supplements and kidney stones, so talk with your healthcare provider about the risks and benefits of supplements for you.
- People taking certain medications. Vitamin D supplements may interact with some medications including diuretics, statins, and steroids. Always speak with your healthcare provider to determine if supplements are recommended for you.
How We Select Supplements
Our team works hard to be transparent about why we recommend certain supplements; you can read more about our dietary supplement methodology here.
We support supplements that are evidence-based and rooted in science. We value certain product attributes that we find to be associated with the highest quality products. We prioritize products that are third-party tested and certified by one of three independent, third-party certifiers: USP, NSF, or ConsumerLab.com.
It’s important to note that the FDA does not review dietary supplements for safety and effectiveness before they go to market. Our team of experts has created a detailed, science-backed methodology to choose the supplements we recommend.
Other health experts we interviewed for insight on choosing the best vitamin D supplement include:
- Kelsey Kunik, RDN, dietitian, nutrition advisor at Fin vs Fin, and sustainable food blogger
- Caroline Thomason, RD, CDCES, dietitian and diabetes educator
- Sharon Puello, MA, RD, CDN, CDCES, dietitian and diabetes educator
What to Look For in Vitamin D Supplements
Supplements that are third-party tested are sent to a lab where they are tested to ensure they contain what they say they contain and are not contaminated with specific high-risk, common contaminants. However, it’s important to note:
- Third-party testing does not test to see if a product is effective or safe for everyone, and it does not ensure the supplement will not interact with other supplements or medications.
- Not all third-party testing is created equal. It is not uncommon for supplement companies to pay labs for certificates after conducting minimal to no testing.
- The third-party certifications we can trust are ConsumerLab.com, NSF, and USP. However, these certifications are difficult to obtain and/or expensive for manufacturers, so many companies choose not to get their products tested by one of these three organizations.
- Sometimes products tested by these three companies are more expensive to try to offset the cost they pay for certification.
- Just because a supplement is not tested by one of these three companies, it does not mean it’s a bad product. We recommend doing some research on the reputability of the manufacturer and calling up the manufacturer and their testing lab to determine their protocols and decide if you feel comfortable consuming the supplement.
In supplements, vitamin D comes in two forms: D2 (ergocalciferol) and D3 (cholecalciferol). Both can raise blood levels of vitamin D, but D3, which is what your body makes from sunlight, is better absorbed by the body. That’s why all our recommended supplements are in the D3 form.
Vitamin D supplements are available as capsules, tablets, softgels, gummies, and liquid. The best form is the one that you will take consistently.
Ingredients & Potential Interactions
It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included, relative to the recommended daily value of that ingredient. Please bring the supplement label to a healthcare provider to review the different ingredients contained in the supplement and any potential interactions between these ingredients and other supplements and medications you are taking.
Vitamin D may be paired with other nutrients for bone health or heart health including calcium, vitamin K, magnesium, and more. It is also found in multivitamins including prenatal vitamins, which contain a variety of vitamins and minerals. Each of these nutrients may interact with medications or other supplements, so always check with your healthcare provider to see if a combination supplement is safe for you.
The recommended dietary allowance (RDA) is 600 IU for kids over the age of one and adults under the age of 70 (it jumps to 800 IU for 70 year olds and older). However, recent research suggests that may not be enough to correct a deficiency, or may not even be enough for some people to maintain adequate vitamin D levels.
One analysis suggests that you may need up to 5,000 IU per day to correct a deficiency, and then at least 2,000 IU per day to maintain adequate blood levels once sufficient levels have been achieved. The Endocrine Society echoes this information in their recommendations. More research is needed in this area, and the exact amount you need will depend on your lifestyle, skin type, age, sun exposure, and current status.
Work with your healthcare professional to determine the best dose for you.
How Much is Too Much?
Vitamin D is a fat soluble vitamin, meaning your body stores any vitamin D not currently in use. Excess vitamin D can be toxic, so over supplementing is a health concern. The effects are long term and include hypercalcemia (too much calcium absorption), which can lead to kidney failure. Excessively high blood levels of vitamin D have also been linked to increased risk of cardiovascular disease and certain cancers.
The tolerable upper intake level (UL) is 4,000 IU per day, though it’s noted that toxicity is rarely seen at levels lower than 10,000 IU per day. Studies with doses of 5,000 IU per day given temporarily to correct a deficiency suggest that it is safe in the short-term.
If you’re taking a higher dose of vitamin D, it’s essential to work with your healthcare provider to monitor your blood levels and ensure you’re not taking too much.
Why Trust Verywell Health
Sarah Anzlovar, MS, RDN, LDN, is a registered dietitian with her master’s degree in nutrition communication from the Tufts Friedman School of Nutrition Science and Policy. She owns a private practice in the suburbs of Boston, where she helps her clients ditch diets and learn to eat foods that help them feel their best and achieve optimal health. Sarah is also a freelance writer, where she lends her expertise in translating the research on a wide variety of nutrition topics into relatable and approachable recommendations for consumers.