Finding the best vitamin D supplement can depend on various factors, such as age, dose, and how they are taken. Mindbodygreen, Ritual, and NOW are some of the best brands for vitamin D supplements.
This article looks at how much vitamin D people need by age, who may need a supplement, and some options to consider. It also discusses how to get more vitamin D naturally.
How we chose
Medical News Today chooses products that fit the following criteria:
Safety: The products contain safe doses of vitamin D for adults.
In supplements, two forms of vitamin D are available: D2, called ergocalciferol, and D3, called cholecalciferol. Both are effective, but D3 seems to be more effective at higher dosages.
Manufacturers use yeast to make D2, and they can produce D3 from several sources, including:
For more in-depth resources about vitamins, minerals, and supplements, visit our dedicated hub.
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Who needs to take vitamin D?
Vitamin D is a fat-soluble vitamin essential for healthy bones, immune function, and cell growth.
Some people are more at risk of developing a vitamin D deficiency. According to the National Institutes for Health (NIH), these groups can include:
Infants drinking breast milk: This does not contain much vitamin D. The NIH reports that exclusively and partially breastfed infants receive 10 micrograms (mcg), or 400 international units (IU), of vitamin D per day until weaning.
People who get less exposure to sunlight: People who cannot leave the house, work night shifts, or cover their skin for religious reasons may not get the sun exposure that the body needs to create enough vitamin D. People who live in colder climates may also get less sunlight exposure during the winter months.
Older adults: Older adults who spend more time indoors may be at risk of developing a vitamin D deficiency. According to the NIH, around half of older adults with hip fractures in the United States may have inadequate vitamin D levels. Also, the skin’s ability to synthesize vitamin D declines with age.
People with dark skin: Dark skin tones contain more melanin, which can reduce the amount of vitamin D the skin makes. People with darker skin tones generate vitamin D from the sun more slowly than people with lighter skin. However, it is unclear whether this has any health consequences.
People with obesity: Having a body mass index of 30 or over is associated with lower vitamin D levels, according to the NIH. People who have undergone gastric bypass surgery may also need more vitamin D.
People with malabsorption: Conditions such as inflammatory bowel disease affect the gut’s ability to absorb vitamin D. People with such conditions may not eat foods that contain vitamin D due to dietary restrictions.
How much vitamin D do we need?
A person’s daily requirement for vitamin D depends on age, whether they are pregnant, and whether they have any underlying medical conditions.
Pregnant or breastfeeding people should aim to get 15 mcg (600 IU) of vitamin D per day.
Most people meet at least some of their vitamin D requirements by having safe exposure to sunlight. According to the NIH, spending 5–30 minutes in the sun, with the face, arms, legs, or back exposed, at least twice a week is usually enough.
However, the American Academy of Dermatology Association recommends getting vitamin D through food sources and supplements rather than sun exposure to limit the risk of developing skin cancer.
It is important to note that vitamin D toxicity usually only stems from excessive supplementation rather than from spending a lot of time in the sun or absorbing too much of the vitamin from food.
Vitamin D supplements can also react with certain medications, such as steroids, weight loss drugs, and medications that lower cholesterol. A person should check with a healthcare professional before taking a new supplement.
Safe exposure to sunlight is one of the most effective ways to get more vitamin D, but a person cannot get vitamin D from sitting near a window or outside in the shade.
A deficiency in vitamin D can also lead to rickets, a childhood condition that causes the bones to be softer and more prone to fracture. Most companies fortify milk with vitamin D in the United States, reducing rickets’ prevalence.
A person should contact a doctor immediately if they have new or worsening symptoms after taking vitamin D.
Frequently asked questions about vitamin D supplements
According to the NIH the best way to take vitamin D supplements are via food, sun exposure, and dietary supplementation.
Food: The two main types of vitamin D available in food are D2 and D3. Fatty fish, such as trout and mackerel, and fish liver oil are the best sources of this vitamin. The U.S. and Canada also fortify milk and some milk alternatives with the nutrient.
Sun exposure: UVB radiation can penetrate the skin and lead to the production of vitamin D3. However, the season, time and length of the day, and the weather can influence this. Also, older people and people with more melanin cannot produce as much vitamin D3 from sun exposure.
Dietary supplements: Supplements contain vitamin D2 or D3. While the way the body processes these in the same way, vitamin D3 may increase the amount of serum 25(OH)D for longer than vitamin D2. Low amounts of this serum can indicate a risk of vitamin D deficiency.
The body converts vitamin D into two forms: D2 and D3.
The NIH states that the body appears to absorb the two types at the same rate. The body then turns the vitamin into serum 25(OH)D.
However, levels of this serum are higher and present in the body for longer with D3 than with D2. This may mean a person has a lower risk of a deficiency if they take D3 supplements.
As the NIH notes, people require different amounts of vitamin D at different ages. The recommended dietary allowances (RDAs) are 0–12 months: 10 mcg (400 IU), 1–70 years: 15 mcg (600 IU), over 70 years: 20 mcg (800 IU).
Taken in appropriate doses, vitamin D is safe to take daily. A person should be careful not to exceed the daily recommended doses of vitamin D as taking too much can be toxic. The upper intake level for people over 19 is 100 mcg (4,000 IU). More information on the safe dosages of vitamin D is on the National Institutes of Health (NIH) website.
A person should speak with a doctor before taking any new supplements. They should always follow the instructions on their chosen product and stop using the supplement if they develop any adverse reactions.
Vitamin D is best taken with meals to enhance the absorption into a person’s circulation. Many brands recommend taking the supplement with meals.
According to the National Institutes of Health, vitamin D is fat-soluble. A person can consider taking it with food that contains some fat.
Two forms of vitamin D are available as a supplement, vitamin D3, cholecalciferol, and vitamin D2, ergocalciferol. Both can help correct the body better absorbs vitamin D deficiency, however, vitamin D3 because this is what the body makes from sunlight.
Doctors may prescribe various strengths of vitamin D2 and vitamin D3. Doctors most commonly prescribe vitamin D3 because the body easily absorbs it.
According to a research review, people should avoid taking more than 4,000 IU per day which is the safe upper limit of daily vitamin D. However, the study also reports that the safety of the dose depends on the person’s current vitamin D status, age, and sex.
A person should seek medical advice from their doctor or healthcare professional before taking vitamin D supplements to avoid potential overdose.
Summary
Limited, safe sunlight exposure several times a week can help a person get enough vitamin D, but this may not be possible for many reasons. As a result, some people need to take supplements to get their recommended dose of vitamin D.
A person may only need this supplement during winter, while others may need it year-round.
It is important to note that vitamin D supplements can interact with other medications. As always, check with a healthcare professional before taking a new supplement.
A doctor can take a blood test to look for a vitamin D deficiency. They may then recommend a supplement dosage, considering the person’s age and any other medications.
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