How long does it take to recover from vitamin D deficiency?

In this article:

• Understanding vitamin D
• Recognizing deficiency
• Vitamin D deficiency recovery time
• Strategies to boost vitamin D
• What to expect during treatment
• Maintaining optimal levels

In this article

• Understanding vitamin D
• Recognizing deficiency
• Vitamin D deficiency recovery time
• Strategies to boost vitamin D
• What to expect during treatment
• Maintaining optimal levels

Lots of people take supplements to treat potential nutrient deficiencies, but it’s often just a shot in the dark: without a diagnostic test, it’s impossible to know for certain if you’re actually deficient in anything and how severe your deficiency is. When it comes to vitamin D; however, taking a supplement is less of a guessing game than usual. About 40% of people in the U.S. don’t get enough, and some of those people are deficient enough to have it negatively affect their health. 

If you’ve recently been diagnosed with vitamin D deficiency, it’s important to bring your levels back up to normal as quickly as possible. Here’s what you can expect during treatment, and what to know about maintaining those healthy levels once you reach them.

What is vitamin D, and why does it matter?

Vitamin D is an important nutrient that helps you maintain good bone health, including preventing osteoporosis. Vitamin D also plays a role in your body’s muscular and nervous systems, and gives your immune system a boost, too, helping it fight off illness.

Unlike most other nutrients, though, it’s not that easy to get vitamin D from dietary sources. Some foods are naturally good sources of vitamin D, including fatty fish (like mackerel and sardines), beef liver, cheese, and egg yolks, but most people in the U.S. get it from fortified foods, such as milk, breakfast cereal, orange juice, yogurt, and cod liver oil.

Your body also makes vitamin D when you’re exposed to the sun’s ultraviolet (UV) rays, but this isn’t always a reliable way to get a sufficient amount, especially if you’re wearing sunscreen. If you live in a part of the world that doesn’t consistently get a good amount of sun throughout the year, for example, you shouldn’t rely on UV rays. Other people at risk for not getting enough vitamin D from the sun include older adults and people with dark skin.

How do you know if you are deficient?

The recommended dietary allowance (RDA) for vitamin D varies by age. 

• Babies younger than 1 need 10 micrograms (mcg) per day
• Children between the ages of 1 and 18 years old need 15 mcg per day
• All adults 70 and younger, including pregnant women, need 15 mcg per day
• Adults 71 and older need 20 mcg per day

Most people don’t realize they are deficient in vitamin D unless their deficiency is severe. In children, extremely low vitamin D levels can cause rickets, a condition characterized by soft, weak bones. Developing rickets in childhood can lead to dental problems, impaired growth, skeletal deformities, and increased risk of fractures. But a mild deficiency in vitamin D typically goes unnoticed or causes only nondescript symptoms such as fatigue, bone or muscle pain, muscle weakness, and depressed mood.

Severe vitamin D deficiency can lead to a medical condition called osteomalacia, in which bones soften and weaken due to low calcium levels (vitamin D is required for calcium).

If you think you might be deficient, it’s important to talk to a healthcare provider. They can run a blood test to assess your vitamin D status, usually the 25-hydroxyvitamin D (25(OH)D) levels test. Levels are measured in ng/mL, with 20–50 ng/mL typically considered sufficient for bone health.

How long does it take to recover from a vitamin D deficiency?

It usually takes about six to 12 weeks for your vitamin D levels to get back into a healthy range, assuming you’re consistently following your provider’s supplementation regimen, says Soma Mandal, MD, internist and medical director of women’s health at Hackensack Meridian Health in New Jersey. But if your vitamin D levels are very low, she warns, it can take longer than 12 weeks.  

There are a few other things that can affect the recovery timeline, too, says Dr. Mandal, including:

• The dose of vitamin D and consistency of supplementation: If you have very low vitamin D levels, your provider may put you on a high-dose supplement to get them back into the normal range sooner, but consistently taking your supplement is one of the most important factors in recovery time.  
• Body composition: Vitamin D is a fat-soluble nutrient, which means it’s stored in your liver and fatty tissues. People with higher body fat percentages may need higher doses to reach normal levels because higher amounts of body fat lower the bioavailability of vitamin D, i.e.,  how much of it is absorbed and used by the body.
• Sun exposure: As noted, people who have more regular exposure to sunlight usually have naturally higher vitamin D levels, shortening the recovery timeline.
• Hormonal stage: Age-related changes to bone health after menopause increase a woman’s need for vitamin D, so it can take longer for postmenopausal women to recover from deficiency.

Strategies for boosting your vitamin D levels

The most reliable and quickest way to boost your vitamin D levels is through supplementation; other sources, such as dietary intake and sun exposure, are not generally considered as effective at getting levels back within the normal range. 

Taking supplemental vitamin D3 is one of the best strategies for increasing your levels. Vitamin D3 is the type your body produces when exposed to the sun, and is also found in animal sources of vitamin D; compared to vitamin D2, which comes from plant and fortified food sources, vitamin D3 is generally considered to raise blood levels of vitamin D better and help you maintain those levels for longer.

Even if you’re taking a supplement, though, there are still other ways to continue boosting your vitamin D levels. Mary Van, Pharm.D., a pharmacist and nutritionist based in Fort Lauderdale, Florida, recommends getting a daily dose of sun, especially first thing in the morning and early in the evening, when UV rays are gentler. One study suggests spending between 5 and 30 minutes in the sun to soak up the vitamin D you need, but keep in mind this should be done carefully to avoid skin damage and a higher risk of skin cancer; the fairer you are, the less time you need to spend, and, as Dr. Van says, try to avoid the midday sun (10 a.m. to 2 p.m.), when the UV rays are strongest.

Dr. Van also suggests pairing your vitamin D supplementation with vitamin K2 or orange juice, which can help your body absorb more of your supplement. Similarly, some experts recommend consuming a small amount of dietary fat (such as nuts, seeds, fatty fish, or avocado) with your vitamin D because it can help you better absorb it, and taking it with the largest meal of the day. 

What to expect during treatment

Once you commit to a supplementation plan, Dr. Van says you should start to feel better within a few weeks of hitting your optimal vitamin D levels. Dr. Mandal agrees, noting that symptoms like fatigue, muscle aches, and low mood often begin to improve after a few weeks of treatment. More significant improvements, though, can take up to two or three months. Dr. Mandal says she typically rechecks her patients’ labs around eight weeks.

Keep in mind that high amounts of vitamin D can lead to vitamin D toxicity, which causes symptoms like weakness, fatigue, loss of appetite, and bone pain. Since vitamin D is fat-soluble, the body cannot easily get rid of excess and it can build up in fatty tissues and remain for a long time.

She also stresses that vitamin D deficiency is often silent, and just because you don’t notice any improvement doesn’t mean it isn’t happening: “The benefit isn’t always about how you feel day to day. It’s also about long-term bone protection and fracture prevention, particularly after menopause.”

Once your vitamin D levels seem to remain within a normal range, Dr. Van suggests asking your provider to test them at least twice a year (or more often if you have any ongoing risk factors for deficiency). 

Maintaining optimal levels

It’s always better to prevent vitamin D deficiency than treat it, so it’s important to know how much vitamin D you need at every stage of your life, and how best to get it. Maintaining a healthy level in your teens may look much different than maintaining it when you’re 80. 

If you know you have trouble keeping your D levels in the normal range, make sure you have an open line of communication with your provider. Dr. Van says stress, including illness and lack of rest, can trigger low levels; during these times, you may need to resume supplementation. Similarly, aging adults, people with osteopenia or osteoporosis, those with limited sun exposure, those with darker skin, and those with a higher body mass index (BMI) may need continuous supplementation with a maintenance dose, says Dr. Mandal.

If you are at risk of vitamin D deficiency or are experiencing any symptoms—especially fatigue, weakness, muscle or bone pain, or low mood—reach out to a healthcare provider for medical advice. Getting your vitamin D levels tested is a simple procedure that can help you maintain better bone health and avoid future health complications.