Do You Really Need to Take Vitamin D Supplements?

Calcium, fish oil, ginseng, vitamin D. There are a plethora of dietary supplements that you may take for just about anything. The one that sticks out is vitamin D, and you may have heard that it help with bone density. However, there could be risks.

It’s been reported that vitamin D supplements won’t protect healthy, middle-aged adults from osteoporosis. For patients with low bone mass, treatment with an antiresorptive agent or, if bone mass is very low and fractures are present, then an anabolic agent is needed in addition to vitamin D.

Although vitamin D is generally beneficial, there are potential side effects, so supplementation should be used in patients who have low vitamin D levels and who need vitamin D to a normal serum level. Before you stop taking the supplement, make sure you aren’t deficient in vitamin D, says rheumatologist Chad Deal, MD.

“Vitamin D can have a positive impact,” says Dr. Deal. “If you’re healthy and aren’t getting treatment for any medical problems, you don’t have to worry about starting supplements. But if you are now taking supplements, be sure to get your vitamin D levels checked before stopping.”

Groups who need vitamin D or are at risk for vitamin D deficiency include:

• Post-menopausal women.
• Men and women on long-term steroids.
• Elderly people (home-bound or in nursing homes/assisted living).
• Expectant and breastfeeding mothers.
• People with chronic kidney disease.
• People with parathyroid disease.
• Those who have obesity.

“If you aren’t sure if you’re at risk for vitamin D deficiency, ask your doctor to check your vitamin D level,” he says. “They should work with you and repeat the easy blood test required to make sure you’re taking the right amount of supplement.”

Calcium and vitamin D: a partnership

Calcium and vitamin D is the dynamic duo that works together to strengthen and protect your bones. For years, healthcare providers have recommended that postmenopausal women take calcium and vitamin D supplements to prevent osteoporosis, a bone-thinning disease that is a major cause of devastating fractures in old age.

Research linking calcium supplements to heart attack and stroke caused many to take vitamin D supplements alone for prevention.

“Calcium supplements can increase calcification in the arteries and predispose people, especially women, to heart disease,” he says. “That’s why we always prefer dietary calcium. However, some people get adequate dietary calcium but are low in vitamin D.”

What protects from fractures?

For older patients at risk of vitamin D deficiency, supplements can have a major impact. They can prevent osteomalacia, a softening of the bone that makes fractures more likely.

A University of Auckland meta-study reported that vitamin D supplements had little effect on bone density.

“We would not expect vitamin D supplements to have a large impact on bone density unless the deficiency was severe,” he says. “Then their impact could be significant.”

Improving bone density is not the only way to prevent fractures — especially in older patients. Vitamin D can also have huge benefits for muscle function, cognition and falling.

One study found no evidence that vitamin D supplements reduced mortality, or prevented falls or fractures. A different study found no evidence that vitamin D supplements reduced overall mortality. Drilling down into the type of supplement taken, however, vitamin D3 significantly reduced mortality while vitamin D2 slightly increased mortality.

What you can do now

“If you’re concerned about vitamin D deficiency, ask your doctor to check your vitamin D level,” says Dr. Deal. “If the level is low and your provider starts you on supplements, you need repeat testing in eight to 12 weeks to make sure the level is not too high or too low.”

If testing shows your vitamin D level is normal, you need repeat testing every two to three years unless you have major changes in your overall health.

Different diseases need different doses of vitamin D. If you have chronic kidney disease or parathyroid disease, ask your kidney specialist or endocrinologist about the type and dose of vitamin D you need.

If you’re pregnant or breastfeeding, Dr. Deal recommends you keep taking vitamin D supplements as long as your doctor prescribes them. The supplement is linked to healthy development for you and your baby.

For bone health, be sure to stay active and remember to eat a calcium-rich diet. Consult with your doctor frequently to make sure you’re taking the right steps to current (and future) bone health.