Vitamin A status in healthy women eating traditionally prepared spirulina (Dihé) in the Chad Lake area

Abstract

Background: Chad Lake is a central place in a region with a high prevalence of vitamin A deficiency. Spirulina, a natural source of β-carotene, is traditionally produced and eaten as "Dihé" around Chad Lake. β-carotene spirulina has been found to have a high conversion factor to retinol. The aim of the study was to assess if the retinol status between healthy women eating spirulina Dihé daily (SPI+) and not (SPI-) in the Chad Lake area was different.

Methods: This study was observational: 88 healthy women were recruited and selected according to clinical criteria and their willingness to participate. They were divided in two groups according to their Dihé daily consumption: those who eat Dihé (SPI+; n = 35) and those who do not (SPI-; n = 35). After anthropometric and dietary assessments, blood retinol, β-carotene, retinol binding, and inflammatory/nutritional proteins were measured.

Results: The diet between groups was identical, except for β-carotene consumption, which was higher in SPI+ than in SPI- (10.8 vs. 1.8 mg/day). The serum retinol and β-carotene concentrations were significantly higher in SPI+ than in SPI- at 1.26 ± 0.36 μmol/l versus 1.03 ± 0.31 μmol/l (p = 0.008) and 0.59 ±0.37 μmol/l versus 0.46± 0.31 μmol/l (p = 0.04), respectively. Seventy-seven percent of SPI+ versus 29% of SPI- had an adequate blood retinol value (p = 0.01).

Conclusion: The results confirm that β-carotene in spirulina is an effective positive modulator of blood retinol status. Dihé is a potential natural source of β-carotene to achieve a proper vitamin A status in healthy women living near Chad Lake.

Fig 1. Flow chart of the enrolled women divided into the SPI+ and SPI- groups.

Fig 2. Retinol blood concentrations and distribution in the SPI- and SPI+ groups.

The left panel presents all individuals’ blood values, with two red horizontal bars representing the higher value, the adequate blood level of retinol (1.05 μmol/l), and the lower one, which is the cut-off to define a VAD biologically (0.7 μmol/l). The right panel represents the repartition of both groups by using the adequate and VAD blood levels.

Fig 3. Correlations between biological parameters in the SPI- and SPI+ groups.

Fig 4. β-carotene blood concentrations and distribution in the SPI- and SPI+ groups.

All individuals’ blood values were presented for both groups, with two horizontal bars representing the reference ranges used in the laboratory (0.074–0.599 μmol/l).