Arthritis is a common condition characterized by joint pain, stiffness and swelling. It affects over 54 million adults in the United States. There are over 100 different types of arthritis, with osteoarthritis and rheumatoid arthritis being the most common.
Vitamin D is important for bone and joint health, and some research suggests it may help reduce arthritis symptoms. This article provides detailed information on the recommended vitamin D intake for people with arthritis.
Quick answers
The recommended vitamin D intake for people with arthritis is:
- 600-800 IU per day for adults under age 70
- 800-1000 IU per day for adults over age 70
Higher doses up to 2000-4000 IU per day are likely safe and may provide additional benefits. Vitamin D3 (cholecalciferol) is the preferred form.
Vitamin D helps maintain bone health and may reduce inflammation associated with arthritis. Getting enough vitamin D can improve arthritis symptoms like joint pain and stiffness in some people.
Vitamin D is found in foods like fatty fish, eggs and fortified milk. But most people don’t get enough from diet alone and require supplementation. Have your vitamin D blood level checked to determine if you need supplementation.
What is arthritis?
Arthritis refers to over 100 different conditions that affect the joints. It causes pain, stiffness and swelling that can limit mobility and decrease quality of life.
The two most common types of arthritis are:
- Osteoarthritis: Results from wear and tear on joints over time. It most often affects the hands, knees, hips and spine.
- Rheumatoid arthritis: An autoimmune disease where the immune system attacks joint tissue, causing inflammation. It commonly affects smaller joints like those in the hands and feet.
Other types of arthritis include gout, lupus, psoriatic arthritis and septic arthritis. Joint injury or infection can also lead to arthritis.
Symptoms of arthritis
Common symptoms of arthritis include:
- Joint pain and stiffness
- Swelling around joints
- Reduced range of motion
- Tenderness when touching affected joints
- Cracking or grinding noise when moving joints (called crepitus)
- Loss of joint function and flexibility
Arthritis symptoms can range from mild to severe. They may come and go or be constant. Symptoms are often worse in the morning or after periods of inactivity.
What factors influence arthritis risk?
Certain factors can increase your risk of developing arthritis. These include:
- Age: The risk rises as you get older. More than 50% of adults over 65 have some form of arthritis.
- Obesity: Excess weight puts added stress on weight-bearing joints.
- Joint injury: Prior injury from sports, work or accidents increases arthritis risk.
- Genetics: Gene mutations can make some people more prone to developing arthritis, especially autoimmune types.
- Gender: Women have a higher prevalence of some types like rheumatoid arthritis.
Other factors like smoking, occupation, diet and physical activity levels can also affect arthritis risk.
How vitamin D is related to arthritis
Vitamin D plays an important role in bone and muscle health. It may also have anti-inflammatory effects that could benefit arthritis.
Here’s an overview of how vitamin D is related to arthritis:
- Bone health: Vitamin D promotes calcium absorption for strong bones. Weak bones increase arthritis risk.
- Muscle function: Vitamin D activates proteins important for muscle contraction and movement.
- Inflammation: Some research shows vitamin D may reduce inflammatory chemicals like cytokines.
- Pain signaling: Vitamin D may affect nerve signaling pathways involved in pain.
Based on this, getting sufficient vitamin D could potentially help prevent and treat arthritis symptoms like joint deterioration, pain and inflammation.
Vitamin D recommendations for arthritis
Most major health organizations recommend the following daily vitamin D intakes for people with arthritis:
| Organization | Recommended Vitamin D (IU/day) |
|---|---|
| Endocrine Society | 600-800 |
| National Institutes of Health | 600 |
| American College of Rheumatology | 600-800 |
| Arthritis Foundation | 600-800 |
These daily intakes are recommended for generally healthy adults under age 70 years. Older adults over 70 may need higher doses between 800-1000 IU per day.
Some doctors may recommend higher temporary doses around 2000-4000 IU daily to correct vitamin D deficiency. But longer term intakes higher than 4000 IU per day are not recommended without medical supervision.
Key notes on vitamin D recommendations for arthritis
- Intakes are higher for those with deficiencies or malabsorption issues.
- Obese individuals may need 2-3x more vitamin D due to sequestration in fat cells.
- Calcium intake of 1200-1500mg per day is also recommended to support bone health.
- Magnesium aids vitamin D absorption and bone mineralization.
Vitamin D benefits for arthritis
Studies suggest vitamin D may provide the following benefits for people with arthritis:
1. Reduced joint pain
Getting enough vitamin D may decrease arthritis joint pain. In one study, taking 2000 IU vitamin D per day reduced pain by over 20% in knee osteoarthritis patients.
2. Improved physical function
Higher vitamin D levels are linked to better physical function. Older adults with the highest vitamin D levels were 28% less likely to develop disability compared to those with lower levels.
3. Decreased disease activity
Sufficient vitamin D may minimize inflammatory arthritis disease activity, though more research is needed.
4. Slowed joint damage progression
In rheumatoid arthritis patients, adequate vitamin D slowed joint damage over 11 years compared to vitamin D deficiency.
5. Lower flare risk
Vitamin D supplements may reduce painful flares in rheumatoid arthritis. Combining vitamin D with other treatments worked best to prevent flares.
Food sources of vitamin D
Very few foods naturally contain vitamin D. The main dietary sources include:
- Fatty fish like salmon, tuna and mackerel
- Fish liver oils
- Beef liver
- Eggs yolks
- Fortified foods like milk, orange juice, yogurt and cereals
- Mushrooms provide some vitamin D, especially wild mushrooms exposed to UV light
However, most people need to take supplements to reach recommended vitamin D intakes of 600-800 IU per day. Eating fatty fish like salmon 2-3 times per week only provides around 250-500 IU vitamin D.
Key notes on vitamin D from foods
- Fatty fish provide the most vitamin D, though amounts vary widely.
- Fish liver oils like cod liver oil have higher vitamin D but extras are not needed.
- Only 55-60 IU vitamin D is found in 3.5 ounces (100 grams) of farmed salmon fillet.
- Fortified foods provide more consistent amounts but don’t meet full needs.
Vitamin D supplements
Given that food sources are unlikely to provide optimal vitamin D intakes for arthritis, most people need to take supplements.
The preferred supplemental form is vitamin D3 or cholecalciferol. It’s better absorbed and more potent than vitamin D2 or ergocalciferol.
Vitamin D3 supplements are widely available in two forms:
- Tablets: Provide standard doses like 400, 1000, 2000 IU vitamin D3 per tablet.
- Liquid drops: Allow precise dose adjustment, often 400 or 1000 IU per drop.
Multivitamins provide around 400 IU vitamin D3 but don’t meet recommended intakes. Separate vitamin D-only supplements are needed for optimal arthritis dosing.
Tips for taking vitamin D supplements
- Take them with your largest meal for best absorption.
- Choose reputable brands tested for potency and purity.
- Consider taking vitamin K2 to direct calcium into bones not arteries.
- Increase magnesium intake to counteract calcium.
- Don’t exceed 4000 IU vitamin D per day without medical guidance.
Can vitamin D deficiency worsen arthritis?
Yes, there is significant evidence that vitamin D deficiency can increase arthritis symptoms and disease progression.
Studies show those with lower vitamin D levels tend to have more pain, poorer function, lower quality of life and greater disease activity with arthritis.
Severe vitamin D deficiency is linked to faster cartilage loss and joint damage over time. Maintaining sufficient vitamin D levels in the blood may help slow arthritis progression and joint deterioration.
Causes of vitamin D deficiency with arthritis
People with arthritis are at higher risk of vitamin D deficiency for several reasons:
- Less sun exposure from reduced mobility and outdoor activity.
- Medications like steroids that affect vitamin D metabolism.
- Obesity leads to vitamin D sequestration in fat.
- Malabsorption issues can prevent vitamin D absorption.
- Older age diminishes capacity to synthesize vitamin D from sun.
Up to 90% of arthritis patients are estimated to have insufficient blood vitamin D levels. A 25(OH)D blood test can determine your status.
Vitamin D toxicity and side effects
Vitamin D is considered very safe at recommended intakes below 4000 IU per day.
Getting too much vitamin D over time can cause toxicity with excessive calcium buildup. Signs may include:
- Nausea, vomiting, poor appetite
- Increased urination and thirst
- High blood calcium (hypercalcemia)
- Kidney stones
- Bone loss and fractures
- Confusion, disorientation
Vitamin D toxicity is very rare below 10,000 IU per day. Damage occurs more frequently with extremely high long-term intakes over 40,000 IU per day.
To prevent issues, have your 25(OH)D level monitored if taking high dose vitamin D. Reduce intake if blood levels exceed 150 ng/mL (375 nmol/L).
Who should be cautious with vitamin D?
Higher vitamin D doses should be avoided in people with:
- Kidney disease
- History of kidney stones
- Hyperparathyroidism
- Sarcoidosis
- Tuberculosis
- Lymphoma
Check with your doctor before supplementing if you have any medical concerns.
The bottom line
Most major health organizations recommend 600-800 IU of supplemental vitamin D per day for people with arthritis.
Vitamin D helps maintain strong bones and may decrease inflammation associated with arthritis. It’s important to prevent and correct deficiencies.
While vitamin D shows promise for reducing symptoms, more research on optimal dosing is still needed. Have your vitamin D blood level tested regularly and work with a healthcare professional to find the right intake for you.
Frequently asked questions
1. How much vitamin D should I take daily for osteoarthritis?
The recommended daily vitamin D intake for osteoarthritis is 600-800 IU. Some doctors may suggest temporary higher doses around 2000 IU daily to correct deficiencies. Have your blood level monitored to ensure you stay within the optimal range.
2. What vitamin D level is best for arthritis?
Most experts recommend a 25(OH)D blood level between 40-60 ng/mL (100-150 nmol/L) for people with arthritis. Levels under 30 ng/mL (75 nmol/L) are considered deficient and over 150 ng/mL (375 nmol/L) is potentially toxic.
3. Should I take vitamin D in the morning or evening?
For arthritis, the optimal timing is unclear. But vitamin D is best absorbed when taken with food containing fat. Many take it during their largest meal, often dinner. Take supplements consistently at whatever time works best.
4. Does vitamin D interact with arthritis medications?
Very high vitamin D doses may conceivably affect arthritis drugs that target vitamin D pathways. But typical supplements below 4000 IU per day are unlikely to interact. Still, inform your doctor about all supplements you take.
5. Can vitamin D help rheumatoid arthritis symptoms?
Yes, there’s some evidence vitamin D can improve pain, morning stiffness and function in rheumatoid arthritis. It may also help prevent bone loss. However, more research on RA-specific benefits of vitamin D is needed.
