The 9 Best Vitamin D Supplements, According to Dietitians

Where We Stand

For those seeking a standard 2,000 IU dose, Theralogix takes the lead as our top pick because it is third-party tested, NSF-contents certified, easy to swallow, and wallet-friendly. If you prefer a liquid supplement, our favorite option is NOW Supplements Liquid Vitamin D-3, which offers flexibility in dosage by allowing you to take more or fewer drops to meet your individual needs at an affordable price.

Should I Take Vitamin D Supplements?

For healthy individuals with adequate vitamin D levels, there may not be any demonstrable advantages of taking a vitamin D supplement. A vitamin D level of >30 nmol/L is considered adequate to maintain bone health. On the other hand, vitamin D levels less than 30 nmol/L are associated with vitamin D deficiency. If your vitamin D levels are <30 nmol/L, speak with your healthcare provider to determine if a vitamin D supplement would benefit you and at what dosage. 

The following groups of people may benefit from a vitamin D supplement.

• People with osteoporosis. Osteoporosis is a bone disease that leads to a decrease in bone density, which can increase the risk of fractures and falls. Taking a vitamin D supplement helps maintain bone density in men and women with osteoporosis, which can prevent the risk of fractures and falls.  
• Older adults. Older adults are at higher risk for vitamin D deficiency because the skin’s ability to synthesize vitamin D from the sun declines with age. Older adults also tend to spend more time indoors. It’s important to note that Vitamin D supplementation has not been shown to benefit postmenopausal women who do not have osteoporosis or a vitamin D deficiency. However, older adults who are deficient in vitamin D may benefit from taking a supplement. Speak with your healthcare provider to determine the best option for you. 
• Breastfed infants. Breastmilk does not provide adequate vitamin D for infants, so it is recommended that babies who are exclusively breastfed, as well as those who consume under 32 ounces of formula per day, take a daily vitamin D supplement with 400 IU of vitamin D.
• People with limited sun exposure. Spending 10–30 minutes outside each day is enough for most people to obtain adequate vitamin D. However, some people have limited sun exposure due to living in colder climates, wearing clothing that covers the skin, or spending most of their time indoors. If you have limited sun exposure, you could be at risk for vitamin D deficiency. Speak with your healthcare provider to determine if a supplement would benefit you. 
• People with darker skin. Higher amounts of melanin in darker skin reduce the skin’s ability to produce vitamin D from the sun. Therefore, these populations may have lower vitamin D levels. However, it’s unclear if supplementing with vitamin D improves health outcomes in these populations.
• People with fat malabsorption. Vitamin D is a fat-soluble vitamin, which means if the body can’t absorb fat properly, it won’t absorb vitamin D either. If you have a condition that inhibits fat absorption, such as cystic fibrosis, Crohn’s disease, or ulcerative colitis, you could be at risk of vitamin D deficiency and should speak with your healthcare provider about whether supplementation is right for you. 
• People with a higher body fat percentage. Fat cells can essentially trap vitamin D and keep it from being released into the bloodstream. Therefore, people with more body fat may have lower vitamin D levels and may need more vitamin D to achieve optimal levels.
• Those who have had bariatric surgery. Bariatric surgery reduces the absorption of several vitamins, including vitamin D. If you’ve had bariatric surgery, it’s important that you speak with your healthcare provider before taking a vitamin D supplement as recommendations vary from doses of 3,000 IU per day to 50,000 IU several times per week.
• Pregnant people. Getting enough vitamin D during pregnancy ensures healthy bone development of the baby. If you are pregnant and don’t spend adequate time in the sun, you could be at risk of vitamin D deficiency. The RDA for pregnancy is 600 IU per day. The American College of Obstetricians and Gynecologists (ACOG) safely recommends 1,000–2,000 IU per day. Most prenatal vitamins contain this amount, if not more.

The following people may not benefit from taking a vitamin D supplement. 

• Those with adequate vitamin D levels. If you do not have a vitamin D deficiency, taking a vitamin D supplement will likely not lead to increased health benefits. Getting 10–30 minutes of mid-day sunlight several times per week should be sufficient for most people to maintain adequate levels of vitamin D.  
• People at risk for hypercalcemia. Hypercalcemia occurs when there is too much calcium in the blood. This can lead to weakened bones, as well as problems with your kidneys and heart. Vitamin D increases the absorption of calcium. Therefore, if you take a medication that increases calcium levels or have a health condition, like sarcoidosis or primary hyperparathyroidism, and you also take a vitamin D supplement, it could lead to hypercalcemia, which can cause kidney stones and other health problems. Keep in mind that many vitamin D supplements also contain calcium.
• People with chronic kidney disease (CKD). People with CKD may or may not benefit from taking a vitamin D supplement. While kidney disease can affect the body’s ability to convert vitamin D into an active form, the risks of taking vitamin D may outweigh the benefits for some people with CKD. For example, vitamin D increases calcium levels, which can increase hardening of the arteries and heart disease in those with CKD. If you have chronic kidney disease, speak with your healthcare provider to determine if you should take a vitamin D supplement.
• Postmenopausal women without osteoporosis. Vitamin D supplementation is not indicated for postmenopausal women who do not have osteoporosis or vitamin D deficiency. Research shows that vitamin D supplementation in this population does not prevent fractures or falls. In fact, studies have shown that taking vitamin D could increase the risk of fractures and falls in this population, and the USPSTF recommends against supplementation in this population.

Our Supplement Research Process

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, including our staff registered dietitians, has created a detailed, science-backed methodology to choose the supplements we recommend and gives more details on what we specifically look for in supplements.

Our Experts

• Dr. Su-Nui Escobar, DCN, RDN, FAND, menopause dietitian and doctor in clinical nutrition
• Malina Malkani, MS, RDN, CDN, pediatric dietitian, and author
• Sarah Anzlovar, MS, RDN, LDN, intuitive eating dietitian for moms
• Rita Shushy Setrakian, MS, RD, registered dietitian, writer, and founder of Shushy Setrakian Nutrition and Fitness

The Different Types of Vitamin D Supplements

Vitamin D is found in two main forms in supplements, vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Vitamin D2 is mostly found in plants, while vitamin D3 is from animal and plant sources such as lichen. Vitamin D3 is also the form of vitamin D that the body makes from sunlight. Vitamin D supplements are available in capsules, soft gels, tablets, liquids, sprays, and gummies.

Both vitamin D2 and vitamin D3 are well absorbed, and taking them alongside fat enhances absorption. However, research shows that vitamin D3 raises vitamin D levels more than D2.

Ingredients: What to Pay Attention To

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.

Some vitamin D supplements contain other vitamins and minerals such as vitamin K, calcium, or magnesium. Vitamin D is also commonly found in multivitamins and prenatal vitamins. Therefore, if you take a multivitamin with vitamin D alongside a vitamin D supplement, it could result in taking too much vitamin D.

Always check with your healthcare provider before taking a supplement to ensure it doesn’t negatively interact with any other medications or supplements you are taking.

Vitamin D supplements can interact with a number of medications, including the following:

Statins. Taking vitamin D supplements alongside a statin can reduce the efficacy of the statin. Statins reduce cholesterol, and vitamin D is made from cholesterol, so this can reduce how much vitamin D is made in the body.

Steroids. Steroid medications can interfere with vitamin D metabolism and decrease calcium absorption. 

Orlistat. This weight loss drug can reduce the absorption of vitamin D.

Thiazide diuretics. This class of diuretics decreases how much calcium is excreted from the body. If taken alongside vitamin D, this could lead to hypercalcemia (too much calcium in the blood), which can lead to an array of issues, including weakened bones and kidney stones.

Heart and blood pressure medications. Check with your provider before taking a vitamin D supplement if you take heart or blood pressure medications. These medications can cause hypercalcemia when taken alongside vitamin D.  

Multivitamins. If you’re taking a vitamin D supplement and taking a separate multivitamin that contains vitamin D, you could be at risk of taking too much vitamin D, leading to toxicity. It’s recommended to not exceed 4,000 IU of vitamin D per day.

How Much Vitamin D Supplement Should I Take?

The recommended dietary allowance (RDA) for vitamin D, which is the amount needed to maintain healthy bones and calcium metabolism, is as follows:

• Babies <1 year old: 400 international units (IU) per day
• 1–50 years old: 600 IU/day
• Pregnant or breastfeeding: 600 IU/day
• >70 years old: 800 IU/day

However, you may need to take more from a supplement to achieve adequate blood levels of vitamin D. Not everyone needs a vitamin D supplement. If your provider recommends that you take vitamin D, the amount will depend on various factors, including your age, other health conditions you may have, and if you have a deficiency.

To determine if you are deficient in vitamin D, serum 25(OH)D blood levels are measured and are classified as follows:

• <30 nmol/L (12 ng/mL) - Vitamin D deficiency, bone health compromised
• 30–50 nmol/L (12–20 ng/mL) - possible risk of inadequacy
• >50 nmol/L (20 ng/mL) - sufficient for most people
• >75 nmol/L (30 ng/mL) - no increased benefits
• >125 (50 ng/mL) - potential adverse outcomes 

There is no consensus among experts regarding how much vitamin D one should take from a supplement. The Endocrine Society recommends 1,500–2,000 IU per day to maintain adequate vitamin D levels of >75 nmol/L (>30 ng/mL) in adults. However, 75 nmol/L is much higher than the amount considered sufficient for most people, which is 50 nmol/L.

Taking too much vitamin D can lead to toxicity, which most commonly occurs from taking too much vitamin D from supplements. It is not common to get vitamin D toxicity from the sun or food. Vitamin D toxicity can cause dangerously high levels of calcium in the body, kidney damage, and heart arrhythmias. The tolerable upper intake level (UL) for vitamin D is 4,000 IU for ages 9 and older, including those who are pregnant and breastfeeding.

Babies and children should not exceed the following amount of vitamin D per day:

• 0–6 months - 1,000 IU
• 7–12 months - 1,500 IU
• 1–3 years - 2,500 IU
• 4–8 years - 3,000 IU

While it’s recommended that adults don’t exceed 4,000 IU of vitamin per day, some healthcare providers may prescribe a higher dose of vitamin D for a shorter period of time to correct a deficiency. If taking a dose over 4,000 IU, make sure it is under the supervision of a physician.

Best Time to Take a Vitamin D Supplement

The best time to take a vitamin D supplement is with a meal. Vitamin D is a fat-soluble vitamin, meaning that fat helps increase the absorption of vitamin D.

Your Questions, Answered

What’s the best form of vitamin D to take? 

“The most commonly available forms of Vitamin D supplements are Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). Both are beneficial for health, but research indicates that Vitamin D3 is more effective at raising and maintaining adequate levels of vitamin D in the body,” says Dr. Su-Nui Escobar, DCN, RDN, FAND, menopause dietitian and doctor in clinical nutrition.

Keep in mind that if you are following a vegan diet, you’ll want to look for a D3 that indicates it is a vegan supplement, while D2 is derived from plants.

How much vitamin D should I take daily? 

“The amount you need will depend on if you're treating a deficiency (and how deficient you are) or just aiming to maintain adequate stores. The current RDA for vitamin D is 600 IU for most healthy adults, but that may not be enough for many people to even maintain adequate stores, let alone resolve a deficiency,” says Anzlovar.

“Research is now showing that between 1,500 to 2,000 IU may be required to maintain adequate stores in some people and you may need even higher doses in the short-term to replete a deficiency. It's best to have your levels checked before you start a supplement and then work with a healthcare professional to determine the best dose for you,” Anzlovar says. 

What are the symptoms of low vitamin D? 

“Symptoms of vitamin D deficiency include poor sleep, fatigue, bone and muscle pain, muscle weakness, poor appetite, stress fractures, depression, and frequent respiratory infections. In babies and children, vitamin D deficiency can cause rickets, a rare disease that causes the bones to become frail, thin, and deformed, says Malkani.

However, most people don’t actually experience symptoms, says Anzlovar. Or they may not experience them until the deficiency is severe, says Esocbar. “If you're not getting at least 15 minutes of direct sunlight on the majority of your body at least 3 times per week (without sunscreen), you may be at risk for deficiency and it's worth getting your levels checked,” Anzlovar recommends.

What happens if you take too much vitamin D? 

“The Tolerable Upper Limit for Vitamin D is 4,000 IU per day, though short-term higher doses to correct deficiency have been shown to be safe and effective. Since vitamin D is a fat soluble vitamin, your body doesn't excrete any extra you consume, which can lead to hypercalcemia (too much calcium absorption). This could lead to kidney failure and may contribute to other potential health concerns like cardiovascular disease,” says Anzlovar.

Vitamin D toxicity is most often caused by taking too much vitamin D from supplements. It is not common to get too much vitamin D from the sun or food. Therefore, it’s important to read supplement labels and not exceed the upper limit of 4,000 IU per day, unless recommended otherwise by a healthcare professional. 

Who We Are

Lainey Younkin, MS, RD, LDN is a registered dietitian with over 10 years of experience writing about nutrition and health, as well as counseling individuals with various nutrition conditions. She carefully analyzes the most up-to-date research before recommending supplements and always prioritizes supplements that are third-party approved with solid research to support that they are effective.