Impact of consumption of vitamin D fortified foods on serum vitamin D concentrations and vitamin D status in families living in Pune, India: an effectiveness study

Purpose: Research on the effectiveness of food fortification in addressing vitamin D deficiency among Indians is scarce. Thus, this study aimed to assess the effectiveness of consumption of vitamin D fortified foods among families living in Pune, India over 2 years. Methods: Data in this community-based, longitudinal study were collected from 104 families recruited in two arms [Fortified: 51 families (180 participants); Unfortified: 53 families (173 participants)]. Liquid Chromatography Tandem Mass Spectrometry was used to estimate serum 25OHD₂ and 25OHD₃ concentrations. Difference in the mean change in 25OHD₂ concentrations over 2 years between the two arms was the primary endpoint. Improvement of vitamin D status at endline was the secondary endpoint. Results: Consumption of vitamin D rich foods was rarely reported. Participants in the fortified arm consumed an average of 42.5% of the RDA for vitamin D (255 IU vitamin D/day) throughout the study period. Endline 25OHD₂ concentrations in children and adults in the fortified arm were higher by 1.3 and 1.2 nmol/L, respectively, as compared to their unfortified arm counterparts, after adjusting for age and body fat. Neither the change in total 25OHD concentrations nor the improvement in D status were significantly different between the arms. Conclusion: The current vitamin D fortification strategy in India, while effective in maintaining the vitamin D₂ concentrations in both children and adults, was ineffective in improving total vitamin D concentrations or status. There is a need for reassessment of the Indian food fortification policy regarding fortificant type, amount, and vehicle to achieve desired outcomes effectively. Trial Registration: Clinical Trials identifier NCT05541094 (date: 21st March 2023)—retrospectively registered.