Dr. Jacqueline Gerhart: Debate Over How Much Calcium and Vitamin D to Take
Madison, Wisconsin - UW Health Family Medicine physician Jacqueline Gerhart writes a column that appears weekly on madison.com and in the Wisconsin State Journal. Columns are re-published here with permission.
Dear Dr. Gerhart: I'm 85 years old and taking Centrum Silver and extra calcium and vitamin D. I've always had normal bone density. What is the right amount for me to take?
Dear Reader: There is much debate about calcium and vitamin D, and how much is "enough" without taking too much. For calcium and vitamin D, there are risks to taking too much. Too much calcium can lead to kidney stones or even cardiac problems. And, too much vitamin D can be risky because vitamin D is fat soluble – so your body has a more difficult time getting rid of it.
So how much is ideal? In February, the U.S. Preventive Task Force (USPSTF) published that for pre-menopausal women (and men) there is "insufficient evidence" to support taking daily low-dose calcium or vitamin D supplements. In other words, the data that they reviewed showed that the benefits and risks were about the same to adding these supplements if you otherwise are eating a well balanced diet.
Interestingly, for post-menopausal women with normal bone density, they recommended against low-dose daily vitamin D and calcium supplementation – stating that it likely doesn’t help prevent fractures in otherwise-healthy post-menopausal women. However, at the same time the USPSTF data came out, conflicting data was published in a journal called "Osteoporosis International." This journal published that taking calcium and vitamin D in post-menopausal women leads to a 38 percent reduction in hip fracture – and therefore is beneficial.
So what do I tell my patients? I tell them the best plan to help maintain bone health is to eat a balanced diet – including foods with calcium and vitamin D, and to include strength training or resistance activities into their exercise routine. Then, when they reach age 65, they need a "bone mineral density" study to assess if they have any bone loss – also known as osteopenia, or osteoporosis.
You should get this test sooner than age 65 if you have an increased risk of osteoporosis or fractures. The results of this test will determine "how much" calcium and vitamin D you need. One caveat to this is if you already have low calcium or vitamin D levels. Ask your doctor if you should be tested to see if you are deficient.
Now, let me briefly discuss calcium and vitamin D supplementation in people under age 65. Pre-term infants often need supplemental calcium and vitamin D to help their bones develop. Formula-fed babies get calcium and vitamin D from the formula — but check the label to be sure they get the recommended 400 international units per day of vitamin D. Breastfed babies get calcium and vitamin D from breast milk. However, depending on the mother's nutrition and the quantity of milk, further vitamin D may be needed to achieve the recommended 400 IU per day. If supplementation is needed, we recommend vitamin D drops. These can be prescribed by a physician – or purchased over the counter.
For children age 1 to 18, 600 IU of vitamin D are recommended. For calcium, children age 1 to 3 need 700 mg, ages 4-8 need 1,000 mg and ages 9-18 need 1,300 mg. Usually, these levels can be achieved through a balanced diet without supplementation. For age 18-65 – as stated above – there is conflicting evidence. Again, I suggest focusing on dietary sources of calcium and vitamin D, and enhancing your bone health through weight bearing activities.
This column provides general health information and is not specific advice intended for any particular individual(s). It is not a professional medical opinion or a diagnosis. Always consult your personal health care provider about your concerns. No ongoing relationship of any sort (including but not limited to any form of professional relationship) is implied or offered by Dr. Gerhart to people submitting questions.
Date Published: 06/20/2013