Vitamin D plays a key role in supporting bone health, muscle function, and immunity†
You can get vitamin D from the sun, limited food sources, and supplements
Nearly 1/3 of U.S. adults (29%) are Vitamin D deficient 
Vitamin D deficiency♦ can lead to serious health issues
Most adults need a minimum vitamin D daily dose of 1000 – 2000 IU
You may know vitamin D as “the sunshine vitamin” to help support bone health. But did you also know that vitamin D benefits other areas of your health? Vitamin D also supports muscle health and function. And it supports immune health, too! Vitamin D helps to regulate the immune system response and supports immune cell function. † [2,3]
Unfortunately, it’s estimated that 95% of Americans don’t get enough vitamin D from their diet alone. Research shows that up to 29% of U.S. adults have a blood level indicating vitamin D deficiency as determined by a healthcare professional. 
With concerns of vitamin D deficiency, you might be wondering, “How much vitamin D do I need?” What are the effects of vitamin D deficiency?♦ And what are good sources of vitamin D?
Let’s find out.
How Much Vitamin D Do I Need?
The vitamin D recommended daily intake depends on multiple factors, including age, skin color, how much sun exposure you get, where you live (certain geographical latitudes get less sunlight), the season, and whether or not you wear sunscreen.
In general, the recommended amounts of how much vitamin D per day (measured in either micrograms or international units) is below: [2,6]
How Much Vitamin D You Need
Birth to 12 months
10mcg or 400 IU
Children 1-13 years
15mcg or 600 IU
Teens 14-18 years
15mcg or 600 IU
Adults 19-70 years
15mcg or 600 IU
Adults 71 years and older
20mcg or 800 IU
Pregnant and breastfeeding women
15mcg or 600 IU
However, if you’ve got a vitamin D deficiency, you’ll likely need a higher vitamin D dosage —at least temporarily—until you restore your vitamin D levels.
What Are Signs Of Low Vitamin D?
With the prevalence of low vitamin D, you might wonder what symptoms to look for. Vitamin D deficiency♦ may be more difficult to spot. Some less obvious signs of low vitamin D include: [6,7,8]
How much vitamin D should you take if you’re deficient? Talk with your healthcare provider, who will likely prescribe you a vitamin D supplement. The recommended vitamin D dosage for adults at risk for vitamin D deficiency is 1,500-2,000 IU, but your doctor will determine the dosage best suited to your specific health needs.
For patients at risk for vitamin D deficiency♦, the Endocrine Society recommends:
Birth to 12 months: 400-1,000 IU per day
Children 1+ years: 600-1,000 IU per day
Adults 19-70 years: 1,500-2,000 IU
Adults 70+ years: 1,500-2,000 IU per day
Pregnant and breastfeeding women 19-50 years: 1,500-2,000 IU per day
How long does it take to correct a vitamin D deficiency?♦ By taking the prescribed vitamin D dosage, you should see improvements in three to four months.
For more detailed information, see the Vitamin D intakes recommended by the Endocrine Practice Guidelines Committee in the table below:
Life stage group
Endocrine Practice Guidelines Committee recommendations for patients at risk for vitamin D deficiency
0 to 6 months
6 to 12 months
Males & Females
Should I Take Vitamin D or D3?
Whether found in foods or dietary supplements, Vitamin D comes in two main forms: 
Vitamin D2 (ergocalciferol) is in some mushrooms
Vitamin D3 (cholecalciferol) is in beef liver, egg yolks, cheese, oily fish, and fish liver oil
Can you take vitamin D3 every day? Yes! Research shows that vitamin D3 is roughly 87% more potent in raising blood levels of vitamin D and produces two to three times greater storage of vitamin D in the body compared to vitamin D2, thus making vitamin D3 the preferred vitamin D form by the body.
When should you take vitamin D: morning or night? While time of day doesn’t really matter with your vitamin D dosage, many people take vitamins as part of their morning routine. Because vitamin D is a fat-soluble vitamin, it’s absorbed more easily in the presence of dietary fat. For breakfast, this could mean eating some healthy fat such as avocado, full-fat dairy, or eggs with your supplement for best vitamin D absorption.
You can get your vitamin D daily dosage from three main sources: the sun, food, and supplements. While you can spend 10-15 minutes in the sun without sunscreen every day to increase your vitamin D intake, you might be worried about damaging UV rays. That’s why it’s important to ensure your diet includes plenty of vitamin D-rich foods. Good sources include fatty fish, cod liver oils, beef liver, cheese, egg yolks, and mushrooms, as well as vitamin D-fortified foods (such as cereal, milk and orange juice). Finally, taking a vitamin D supplement can fill in any nutritional gaps.
Vitamin D is important for maintaining bone health, muscle functioning, and immune health.† But with up to 29% of U.S. adults having a vitamin D deficiency, you might be wondering, “How much vitamin D should I take?” The daily dosage depends on a variety of factors (including age, skin color, latitude, and more), but in general, it’s recommended that most adults take between 1,500 to 2,000 IUs of vitamin D per day.
Continue to check back on the Nature Made blog for the latest science-backed articles to help you take ownership of your health.
The Journal of Clinical Endocrinology and Metabolism. “Vitamin D(3) is more potent than vitamin D(2) in humans.” December 22, 2010. Accessed on: September 6, 2021. https://pubmed.ncbi.nlm.nih.gov/21177785/
The Journal of Clinical Endocrinology & Metabolism, Volume 96, Issue 7, “Evaluation, Treatment, and Prevention of Vitamin D Deficiency: an Endocrine Society Clinical Practice Guideline.” 1 July 2011, Pages 1911–1930, https://doi.org/10.1210/jc.2011-0385
Lisa Beach is a seasoned journalist whose work has been published in The New York Times, Good Housekeeping, Eating Well, Parents, AARP’s Disrupt Aging, Optimum Wellness, and dozens more. She also writes for a variety of health/wellness-focused brands. Check out her writer’s website at www.LisaBeachWrites.com.
Lynn is a Registered Dietitian (R.D.) and is a member of the Medical and Scientific Communications team at Pharmavite. She has over 20 years of experience in integrative and functional nutrition and has given lectures to health professionals and consumers on nutrition, dietary supplements and related health issues. Lynn frequently conducts employee trainings on various nutrition topics in addition to educating retail partners on vitamins, minerals and supplements. Lynn has previous clinical dietitian expertise in both acute and long-term care, as well as nutrition counseling for weight management, diabetes, and sports nutrition. Lynn earned a bachelor’s of science in Nutrition with a minor in Kinesiology/Exercise Science from The Pennsylvania State University. She earned a M.S. degree in Human Nutrition from Marywood University in Scranton, Pennsylvania. Lynn is an active member of the Academy of Nutrition and Dietetics, Sports Cardiovascular and Wellness Nutritionists, Dietitians in Functional Medicine, and holds a certification in Integrative and Functional Nutrition through the Academy of Nutrition and Dietetics.