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Fernandes and Barreto Junior
550 Rev Assoc Med Bras 2017; 63(6):550-556
REVIEW ARTICLE
Association between physical activity and vitamin D: A narrative
literature review
Marcos Rassi Fernandes1*, Waldivino dos Reis Barreto Junior2
1PhD in Health Sciences, Lecturer Advisor of the Graduate Program in Health Sciences, Faculdade de Medicina da Universidade Federal de Goiás (FM-UFG), Goiânia, GO, Brazil
2MSc. Student of the Graduate Program in Health Sciences, FM-UFG, Goiânia, GO, Brazil
Summary
Study conducted by Graduate Program in
Health Sciences, Faculdade de Medicina
da Universidade Federal de Goiás
(FM-UFG), Goiânia, GO, Brazil
Article received: 10/13/2016
Accepted for publication: 11/20/2016
*Correspondence:
Address: Av. Azaleias, Qd 10, Lt 20
Aparecida de Goiânia, GO – Brazil
Postal code: 74935-187
This narrative review of the medical literature assessed whether outdoor and
indoor physical activity would increase the plasma levels of vitamin D.
Synthesis of this liposoluble vitamin is mainly mediated by sunlight on the
skin, where it is activated to perform its main action, which is to control the
serum levels of calcium as soon as the element is absorbed in the intestines,
assisting in the regulation of bone metabolism. Physical activity is any body
movement that results in energy expenditure, while outdoor physical activity
refers to physical activity carried out at public parks or other open spaces, as
is the case of the popular practice of taking walks. Exercising outdoors would
have both the benefits of physical activity and of sun exposure, namely the
synthesis of vitamin D. However, according to the studies analyzed, increased
plasma concentration of vitamin D occurs with physical activity both indoors
and outdoors.
Keywords: vitamin D, physical activity, environmental exposure, sunlight,
external work environment.
Introduction
Vitamin D is a liposoluble compound with antioxidant
properties, essential for maintaining the body’s min-
eral balance. It can be acquired from an exogenous source
(feed) or endogenously synthesized from the incidence
of the sun’s ultraviolet rays on the skin. Although it is
a vitamin, it is also considered a hormone, since its ac-
tivation is made by means of chemical reactions inside
the organism.1
Vitamin D occurs in the form of two biologically in-
ert precursors or prohormones, vitamin D2 (ergocalcif-
erol) and vitamin D3 (cholecalciferol). Ergocalciferol is
of vegetable origin, whereas cholecalciferol is of animal
origin, being formed by ultraviolet B radiation on 7-de-
hydrocholesterol.2 Vitamin D in these forms must be
converted into active hormone to be able to exert bio-
logical influence on mineral metabolism and other phys-
iological functions.1
Physical activity is any movement of the body pro-
duced by skeletal muscles that results in greater energy
expenditure than that of rest levels. Performing physical
activity in an outdoor environment, with sun exposure,
would provide benefits both from the physical work itself
and from vitamin D synthesis and action in the body.3
Based on current evidence, our narrative review of the
literature aimed to answer whether physical activity
performed both outdoors (with sun exposure) and in-
doors (without sun exposure) would increase vitamin
D plasma levels.
Historical aspects
Elmer V. McCollum at the end of the 19th century, in ex-
periments on fats associated with the cure of certain dis-
eases (rickets), observed how this process took place in the
organism and its relation in the interruption of inadequate
bone mineralization during growth due to lack of sun
exposure. Today, this substance is called vitamin D. 4
Physical activity has always existed throughout his-
tory, both indoors (Figure 1) and outdoors5 (Figure 2).
Millennial accounts of Greeks, Chinese and Indians in
relation to the practice of physical activity affirm the idea
that a stimulated body becomes strong regardless of
variation in the environment. The important thing is for
the individual to become an adept of this practice. 6,7