In the same Finnish cohort that found doses
of vitamin D in excess
of 2,000 IU per day during infancy to powerfully protect against type 1 diabetes (see sidebar «Vitamin D and Type 1 Diabetes below), regular supplementation with vitamin D was associated with a 33
percent increased risk of atopy and allergic rhinitis compared to irregular or no supplementation; among those who supplemented regularly, the data suggested that supplementation with 2000 IU or more per day may
increase the
risk of asthma by as much as four times compared to regular supplementation with lower doses, although the study lacked the statistical power to determine whether or not this apparent effect was due to chance.34