Cross-sectional analysis of universal vitamin D supplementation in former East Germany during the first year of life

Background: Universal vitamin D supplementation is controversial. Preventative examinations and public health initiatives in former East Germany that included vitamin D prophylaxis for children were regulated by official recommendations and guidelines. The aim of this study is to analyse the impact of a standardised nationwide guideline for universal supplementation with 400 International Units (IU) vitamin D3/day during the first year of life on clinical and biochemical parameters and the influence of surrounding factors.

Methods: This is a cross-sectional analysis looking at data from a field study of 3481 term-born children during their first year of life that was conducted in 1989.

Results: There were no significant clinical signs of rickets. 25 hydroxyvitamin D (25(OH) D) (mean and SEM, total analyses n = 572) after birth (n = 28) was 36(7) nmol/L, at 1 month 64(4) nmol/L (n = 70, p <0.0001), 91(5) nmol/L at 3 months (n = 95, p <0.0001), 65(8) nmol/L at 8 months (n = 21, p = 0.005) and ranged between 33 and 109 nmol/L until 12 months. Less than 0.2% of analyses revealed pathological levels for calcium or phosphate. Alkaline phosphatase (ALP) levels (n = 690) were > 1500 U/L (95th percentile) in 3.6%. Participants were on breastmilk or vitamin D-free formula, with solids added from 6 months of age. There were seasonal variations in 25(OH) D levels with a rise during spring and autumn. Thus this analysis is unique as sun exposure and supplementation can be considered as the only vitamin D sources.

Conclusions: We conclude that universal supplementation with 400 IU of vitamin D3 during the first year of life is safe and provides sufficient 25(OH) D levels in Germany.