Do You Need Extra Vitamin D? 6 Facts to Consider

Meghan Veno, MD is a board-certified primary care physician practicing family medicine at Inova Primary Care – Ballston. Dr. Veno believes in preventive care and a holistic approach to patient care. Her favorite aspects of patient care include adolescent medicine, sports medicine and comprehensive diabetes care.

Vitamin D is an essential nutrient — it helps our bodies absorb calcium and keeps our bones strong. But finding the balance between getting too little and too much isn’t always easy.

There are three ways to get vitamin D — sunlight, food and supplements. But vitamin D deficiency is common: 35% of American adults don’t get enough. So how do you know whether you need to take a supplement or increase the supplement you’re taking? And how can you be sure you’re not overdoing it? The answer’s not simple and varies from person to person.

To better understand whether your body may need extra vitamin D, consider these facts:

Not Many Foods Are Naturally High in Vitamin D

Unlike other vitamins and nutrients, vitamin D does not occur naturally in many foods. But if you regularly eat foods high in vitamin D, you may get more than you think.

Natural sources of vitamin D include:

• Canned tuna
• Cod liver oil
• Egg yolks
• Salmon
• Sardines
• Swordfish

You’ll also find higher levels of vitamin D in some manufactured foods including fortified milk, cereals and orange juice. Some mushrooms provide a larger dose of vitamin D when the grower treats them with UV light.

Sunlight May Not Provide All the Vitamin D You Need

Sunlight is the most natural way to get vitamin D — your skin naturally creates it when directly exposed to the sun’s ultraviolet B (UVB) rays.

The problem is that UVB rays are harmful to the skin and avoiding direct exposure is critical in preventing skin cancer. And sun protection, such as sunscreen and clothing, limits how much vitamin D your skin can produce.

Age and skin pigment also affect how much vitamin D your skin makes. As skin ages, it loses its ability to produce vitamin D efficiently. In people of color, the higher melanin content in darker skin works like sunscreen, blocking the sun’s UVB rays.

Some Health Conditions Increase the Risk of Vitamin D Deficiency

Sometimes health issues interrupt the body’s ability to absorb or process nutrients like vitamin D. People who live with those conditions and have weak bones, complain of bone pain or suffer recurrent fractures might have a vitamin D deficiency — a risk factor for developing osteoporosis.

Conditions that can lead to deficiency include:

• Eating disorders, such as anorexia or bulimia
• Kidney or liver disease, which can impair metabolism
• Malabsorption digestive disorders, such as Crohn’s disease and celiac disease
• Obesity, which can prevent vitamin d from reaching the blood

Certain medications, including some cholesterol medicines, anti-seizure drugs and corticosteroids, can affect how you metabolize vitamin D. Taking these medications puts you at higher risk for vitamin D deficiency.

Pregnant Women and Breastfed Babies Should Take Vitamin D Supplements

Getting the right amount of nutrients during pregnancy is vital for the baby’s development and growth. While prenatal vitamins go a long way to provide more nutrients, they don’t offer enough vitamin D.

Vitamin D deficiency during pregnancy can impact fetal growth and disrupt neonatal development. It also increases the baby’s risk for infantile rickets — a condition marked by soft and deformed bones. To maintain healthy vitamin D levels, experts suggest women take extra vitamin D while pregnant with a recommended supplement of 600 international units (IU) per day. But it’s always best to consult your provider before taking any over-the-counter supplements, especially during pregnancy.

Breastfed babies also need a vitamin D supplement, whether they’re breastfed exclusively or in combination with formula feeding. Unlike infant formulas (which are fortified with vitamin D), breastmilk does not provide enough. Infants who are only formula-fed do not require supplementation.

Not Everyone Should Take the Recommended Dose of Vitamin D

The recommended vitamin D supplement for adults is 600 to 800 IU daily. But where you fall in that spectrum depends on your age, health and lifestyle. If you primarily spend your days in a windowless office or live in a place that doesn’t see much sunshine, you may need a higher vitamin D supplement than a gardener in California.

The medications you take can also guide your vitamin D supplement. Just as some drugs can increase your risk for a vitamin D deficiency, taking the wrong dosage of vitamin D supplements may compromise your prescription medications.

Any time you plan to take a new medication, check with your provider to identify the proper dosage and any possible drug interactions. A vitamin D supplement is no different. And let your provider know which supplements you already take — your multivitamin may already provide extra vitamin D.

Experts no longer recommend screening for vitamin D deficiency in the general population. But your provider can tell you if you are at risk for deficiency and should supplement. Learn more: Vitamin D Tests – When you need them and when you don’t.

It Is Possible to Take Too Much Vitamin D

Many people believe that you can’t take too much of a vitamin — that your body will rid itself of the excess. But that’s not the case with vitamin D.

Overdosing on vitamin D, called hypervitaminosis D, is rare. But taking too much for too long does present some health risks. Vitamin D helps your body absorb calcium, and too much may also cause an unhealthy increase in calcium levels — a condition known as hypercalcemia.

Symptoms of hypercalcemia include:

• Confusion
• Frequent urination
• Lack of appetite
• Muscle weakness
• Vomiting

Untreated hypercalcemia can cause cardiac issues, calcium deposits in the kidneys and bone pain. But if you follow your provider’s recommendations and don’t take a high-dose supplement when you aren’t deficient, overdose should not be a concern.

To learn whether you should take vitamin D supplements, schedule an appointment with your PCP. If you do not have a PCP, we welcome you to make an appointment with a provider at any of our Primary Care locations.