Vitamin D3 25 mcg (1000 IU) Supplement

Osteoporosis is a major public health issue affecting bone health that is becoming more common in both women and men. Learn more about supplements that may support your goal of having and maintaining strong bones.

Most studies show that Vitamin D’s absorption and effectiveness are not dependent on time of day.† However, because it is fat-soluble, taking it with a meal that contains some healthy fat may support absorption.† The most important factor is taking it consistently each day to help maintain adequate vitamin D levels.†

Some emerging research suggests that very high levels of vitamin D might influence the body’s natural melatonin production, which plays a role in regulating sleep.† If you have concerns about vitamin D and sleep, it’s best to consult with your physician for the dosage that is right for you.

If you are taking Coumadin  (warfarin), we recommend consulting your doctor before adding any supplements to your diet.

Vitamin D supports many aspects of health, including bone maintenance and calcium absorption.†  A study published in The Clinical Journal of Pain found obese individuals with knee osteoarthritis who had higher levels of vitamin D experienced less knee pain than those with deficient or insufficient levels of vitamin D†. In the study of 256 middle-aged and older adults with osteoarthritis, the participants provided a self-report of knee pain and completed functional performance tasks that included balancing, walking and rising from a sitting position to a standing position. The participants with healthy vitamin D levels had less knee osteoarthritis pain, and could also walk, balance and rise from sitting to standing better than obese participants with insufficient vitamin D levels.†

How much is needed varies considerably based on age, skin tone, time of year, sun exposure, where one lives, weight, and other factors. Cooper Clinic suggests consulting with your physician on your specific intake based on your vitamin D test results, age, and health issues.

The recommended target level for vitamin D is open to debate. Most experts agree your vitamin D level should be at least 30 ng/ml. However, doctors at the Cooper Clinic in Dallas, Texas, recommend patients target at least 40 ng/ml as a baseline. A level of 50 ng/ml is considered optimal for brain health.

Vitamin D levels can vary based on factors such as season, location, sun exposure, and skin tone. Limited exposure to sunlight—whether due to lifestyle, use of sunscreen, or geographic location—can reduce the body’s natural vitamin D production. Food sources of vitamin D are limited and include options like fatty fish, cod liver oil, fortified dairy products, and cereals. People living in northern regions, and individuals with darker skin—due to higher melanin levels that reduce UV absorption—may have a higher likelihood of lower vitamin D levels.

The only way to know your vitamin D level is to have a blood test known as 25 hydroxyvitamin D. Because vitamin D comes from food, sunshine, and dietary supplements, the amount needed can vary from person to person. In blood tests, vitamin D (25-hydroxyvitamin D) is measured in either nanomoles per liter (nmol/L) or nanograms per milliliter (ng/mL). One nmol/L equals 0.4 ng/mL, so 20 ng/mL is the same as 50 nmol/L.

According to public health guidelines, levels below 12 ng/mL (30 nmol/L) are considered very low, while levels above 50 ng/mL (125 nmol/L) may be higher than recommended. If you’re unsure of your vitamin D status or whether supplementation is appropriate, consult your healthcare provider.

Several factors may contribute to low vitamin D levels. One common reason is limited sun exposure, often due to the use of sunscreen, which can significantly reduce the skin’s ability to produce vitamin D. For example, sunscreen with SPF 15 has been shown to decrease vitamin D synthesis by up to 99%. Other factors such as spending more time indoors and certain health conditions—including higher body weight—have also been associated with lower vitamin D levels.

While vitamin D3 can be taken with or without food, some research suggests it may be better absorbed when taken with a meal containing fat. For example, a study published in the Journal of the Academy of Nutrition and Dietetics (February 2015) found that vitamin D3 absorption increased by 32% when taken with a meal where 30% of the calories came from fat. As individual responses can vary, you may wish to take your supplement with a balanced meal for optimal absorption.