A new study out of Brazil has found that many older Brazilian men are vitamin D deficient, despite living in the tropics.
Located near the equator, Brazil receives high amounts of direct sunlight, enabling year-round, natural vitamin D production. In theory, this would translate into the Brazilian population having good and adequate levels of vitamin D.
In this new study, researchers looked at older Brazilian men in Recife, a city located in a region of Brazil known to have very high levels of sunlight.
Researchers sampled 234 men older than 60 years during the sunniest months. They calculated the sun index, noted skin phototypes, and measured serum vitamin D levels and calcium intake.
The researchers found that 31.5% of the participants were deficient in vitamin D (<20 ng/mL) and 66.7% were insufficient (<30 ng/mL). The researchers also found that 72% had low calcium intake.
Of the sample population, 65% made less than $4,200 USD in annual family income and only 2% reported taking vitamin D supplements.
The researchers speculated that there are a few different reasons that might explain the low vitamin D levels found in this population.
To start, since it was an older population, they may not seek enough sun exposure for their darker skin types. They also noted that it’s more difficult for older populations to produce vitamin D because their skin gets thinner and is unable to produce as much vitamin D as younger persons.
The researchers lastly mentioned that food fortification is low in Brazil, and many cannot afford supplementation.
Cabral, MA et. al. Prevalence of vitamin D deficiency during the summer and its relationship with sun exposure and skin phototype in elderly men living in the tropics. Clinical Interventions in Aging, 2013.