Vitamin D Exposure for Optimal Bone Health

July 22, 2020

Managing vitamin D levels may not be as straightforward as it would seem. There are factors that should be considered that are not often communicated to patients. In today's edition of Overdrive, the Rheumatology Network podcast, we talk with Dr. Suzanne Jan de Beur of Johns Hopkins University School of Medicine. She serves as director of endocrinology at Johns Hopkins Bayview Medical Center and president-elect of the American Society for Bone and Mineral Research.

This transcript represents just a portion of our discussion with Dr. Jan de Beur. To hear this discussion in its entirety, click play on the audio version.

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Dr. Jan de Beur: I’m Suzanne Jan de Beur. I’m associate professor of medicine at Johns Hopkins University School of Medicine and I’m also the President-Elect of the American Society of Bone and Mineral Research.

Rheumatology Network: Welcome to the Rheumatology Network podcast. Today, we’re focusing on osteoporosis. There is a lot of evidence that is published on a regular basis and there’s probably a lot of conflicting information out there. So what we wanted to do today is discuss best practices for physicians who treat patients with rheumatic disease and whether or not they should be taking vitamin D, how much and in what form. Should it be sun? Should it be a supplement? So those are some of the things we’re going to be talking about today. So, let’s talk osteoporosis. How important is it to continue taking---to reach a healthy level vitamin D?

Dr. Jan de Beur: We know that vitamin D is important for a number of bodily functions. It’s really important for skeletal health. It’s important for skeletal mineralization. And, a lot times the only way we get vitamin D and the main way we make vitamin D is through exposure of our skin to sunlight. So, in a situation where we are at stay at home orders or maybe not getting out as much as we usually do, people are going to get less exposure to their skin and be making less vitamin D.

There are very sources of vitamin D and many of the dietary sources of vitamin D are not that palatable, such as fatty fishes and fish oils. And, they generally contain not a lot of vitamin D. There are supplemented foods like dairy products in the U.S. that do have some small amount of vitamin D supplementation, but again, it’s a lot less than the daily recommended amount of vitamin D.

So, if people aren’t getting sun exposure or if they are covering up or wearing sun screen because they’re trying to reduce their risk of skin cancers, or reduce the signs of aging---really, they’re not getting vitamin D through skin synthesis through sun exposure. Dietary amounts are usually low and, they’re inconsistent, and supplemented dietary amounts are low.

Generally, we recommend vitamin D supplementation because you know how much you’re getting, you can do it basis, and you’re not required to hide your skin exposed to the sun.

Rheumatology Network: Which is a good thing for patients with rheumatic disease who may be at high risk of melanoma and other skin condition.

Dr. Jan de Beur: Yep,and can have sun sensitivity that can cause certain rashes and flare up of their disorder, so that’s exactly right.

Rheumatology Network: Recently, the American Society for Bone and Mineral Research of which you are current president-elect has just issued a joint guidance on vitamin D in conjunction with European Calcified Tissue Society, the Endocrine Society, the American Association of Clinical Oncologists, and the National Osteoporosis Foundation, including the International Osteoporosis Foundation. That’s a lot, but these are some pretty heavy hitters when it comes to guidance on osteoporosis. So, tell me, what they recommended in terms of vitamin D guidance in the era of COVID-19.

Dr. Jan de Beur: Yeah, so it is. It’s a joint statement and with seven different societies, including international societies. So, a lot of expertise and expert opinion went into issuing this guidance. I think the way it came about was there was some initial publications that showed that those with lower vitamin D levels in their blood had poorer outcomes with COVID infections.

So, the guidance is for two reasons:1) to encourage people to be vitamin D sufficient and to make sure they’re getting vitamin D but 2) also to put that data in perspective as far as expectations for what vitamin D can do with respect to COVID. So, in the first part, it’s very important that we are focusing a lot on COVID and COVID is keeping a lot of people from getting their regular medical care. One of the things we want to make sure is that people maintain their regular medical care and their regular medical routine. So, for people with osteoporosis or skeletal health issues, it’s really important to be able to continue to get your calcium and vitamin D. And, many of us are not getting outside as much because we’re staying indoors because our normal activities have been curtailed. So, for those are who are not getting their vitamin D through sun exposure, we recommend supplementation and the Institute of Medicine recommends between 400 IU of vitamin D to 1,000 IU of vitamin D daily. Other experts might recommend that you achieve a certain serum level of vitamin D to have the skeletal benefits of vitamin D. So this statement says in consistent with the IOF recommendation, 400 units to a 1,000 units of vitamin D supplements per day for those who are not getting at least 15-30 minutes of sun exposure without sunscreen on their skin.

Rheumatology Network: So its either or, not both sun and supplement?

Dr. Jan de Beur:In the summer months, generally between March and November the sun rays are strong enough to be able to produce vitamin D through sun exposure. From November through March in the winter months the sunlight exposure the UV exposure is less. You make less vitamin D when you’re out in the sun. But certainly during this time of year between 15 and 30 minutes on skin that’s not covered and doesn’t have sun screen on it---is a good way to get enough vitamin D.

Rheumatology Network: What are the target serum levels we should aim for?

Dr. Jan de Beur: This is very controversial. But generally we think about 30 ng/dL is where we start to see the skeletal benefits. So generally that level of vitamin D exposure from the sun or through supplementation can get you to that level. Although people who are older and people with darker pigmented skin may require more exposure to make the same amount of vitamin D. In a situation with older individuals, their skin is less efficient at making vitamin D. And, in adults with higher pigmented levels in their skin, that their skin also makes less vitamin D per UV exposure.

Rheumatology Network: Hmm. I didn’t know that, but all the more reason to see your doctor to get an appropriate prescription. So that you know exactly how much you should be taking.

Dr. Jan de Beur: Yeah, your doctor can measure your levels and you can make sure that you are taking enough.

Rheumatology Network: What did the team say about calcium? What are the recommendations for taking calcium?

Dr. Jan de Beur: This guidance really didn’t lay out the calcium recommendations, but consistent with the Institute of Medicine, generally we think that people should get 1,000 mg of calcium a day and that should be taking into account their dietary calcium and adding on top of that their supplement. I think what happens is that people sometimes get the advice, ‘Oh, take 1,000 mg of calcium a day,’ and it’s not taking into account calcium in diet. Things like dairy products are rich in calcium. Almond products are rich in calcium. So, there are dietary sources of calcium and many people get a lot in their diet and may not need any supplementation or just a tiny fraction of that…..

This transcript represents just a portion of our discussion with Dr. Jan de Beur. To hear this discussion in its entirety, click play on the audio version.