SUPPLEMENTS: Easy on the Vitamin D
September 18, 2019 • 1 min read
-- Vitamin D supports bone density, so taking a bigger daily dose will make your bones even stronger. Not so fast.
In fact, a recent study of healthy adults demonstrated the opposite effect.
The three-year study involved 311 healthy adults, without osteoporosis, taking daily doses of 400, 4,000 or 10,000 units of vitamin D. CT scans calculated bone density at the beginning and end of the study.
Declines in bone mineral density in the participants’ arms were 1.2% for the 400 group, 2.4% for the 4,000 group, and 3.5% for those taking 10,000 units a day. In the leg bones, declines were statistically significant in the 4,000 and 10,000 groups, but not in the 400 group.
In view of the surprising results, study investigators concluded healthy adults should stick to recommended doses of vitamin D. The U.S. National Academy of Medicine considers 600–800 IU of daily vitamin D to be sufficient for the majority of the population, the U.S. Endocrine Society recommends 1,500–2,000 IU per day.
The study also indicated a potential safety concern with taking high levels of vitamin D, with higher daily doses (4000 IU and 10,000 IU) linked to hypercalciuria (elevated levels of calcium in the urine) – a condition associated with increased risk of kidney stones and impaired kidney function.
Vitamin D is often referred to as “the sunshine vitamin” because the sun is one of the best sources of this nutrient. Other good sources include fatty fish and seafood.