Markus Juonala: Vitamin D and Heart Risk
An Interview with Markus Juonala: Vitamin D and Heart Risk
Michael F. Shaughnessy
1) Dr. Juonala, could you tell us a bit about yourself and your education and experience.
I am a specialist in Internal Medicine and Endocrinology. Within the Cardiovascular Risk in Young Finns Study, I have been conducting research on the importance of childhood cardiovascular risk factors since 2001. Currently, I am working as Professor of Internal Medicine in University of Turku, Finland.
2) What first got you interested in Vitamin D and the heart?
Within my specialization in Endocrinology it became evident that the effects of vitamin D might not be only on bone metabolism, but also on cardio metabolic health.
3) How many subjects were in your study and what did you find out?
Our study included 2,148 subjects from the Cardiovascular Risk in Young Finns Study, aged 3-18 years at baseline (in 1980). Subjects were re-examined at age 30-45 years (in 2007). Children with 25-OH vitamin D levels in the lowest quartile (<40 nmol/l) had significantly increased odds of having high levels of carotid intima-media thickness, a marker of early atherosclerosis.
4) Do you have any idea as to this relationship?
Earlier studies have shown that vitamin D inhibits vascular calcification. It is also a potent immune modulator. Vitamin D may also be a negative endocrine regulator of renin-angiotensin system36.
5) I have been to Rauma, Lahti, Helsinki, and Turku—and I guess that you do not get very much natural sunlight- which contains Vitamin D. How much should children, adolescents, and adults get?
Not quite enough, as current dietary recommendations in Finland suggest that children aged 2-18 years should have a vitamin D supplementation of 7.5 microg/day throughout the year
6) Lack of Vitamin D can also lead to stroke—-am I correct on this?
There are some studies suggesting this, but as with our finding, epidemiological studies cannot prove causality.
7) Why does Vitamin D seem to be important in children?
It is difficult to say based on our study.
With vitamin D, it seems to be that it is bad if you get too much or too little, as the relationship is similar to a J curve.
9) What have I not asked?
I think these questions were pretty thorough.