Page 26 - Waterfall City Issue 3 March 2025

Waterfall City Health

HOW MUCH VITAMIN D

do you need? It’s complicated…

By Dr Jayalakshmi Narainsamy, specialist physician and endocrinologist practising at Netcare

V itamin D, commonly known

as the sunshine vitamin
because sunlight helps
our bodies to produce it,
is essential for maintaining strong
bones and a healthy immune
system. However, too much can have
adverse effects on your health.

Vitamin D involves a complex interplay
between environmental and individual
factors. Either deficiency or overdose
of vitamin D can affect overall health,
yet understanding individual vitamin D
requirements can be complicated.

Individual factors such as having darker
skin, cultural aspects, pre-existing
illnesses, higher Body Mass Index
[BMI] and our modern lives’ tendency
toward more indoor activities, may also
contribute to vitamin D deficiency even
where there is bountiful availability in
sunny climates, such as ours.

Most studies on vitamin D deficiency
have been conducted in other
countries, where the climate, 62,9%, while 35,7% of coloured South Apart from the risks to skeletal health,
demographic and socioeconomic Africans, 14,7% of Indian South Africans the effects of vitamin D deficiency
factors differ from our local context. and 8,9% of white South Africans are being studied in more detail for
Data on South African populations experienced deficiency of this key wider-ranging consequences. One
is scarce and a lot more complicated nutrient. meta-analysis suggested that vitamin
to interpret given the different sun D supplementation reduced cancer
exposures across provinces, different Why do our bodies need mortality. While cardiovascular risk
ethnic groups and general lack of vitamin D? reduction has not been conclusively
recent information. Vitamin D is responsible for regulating proven, there have been studies, which
the calcium levels in our cells, therefore showed benefits in reducing blood
A meta-analysis of data from studies a deficiency of vitamin D also leads to pressure, reduction of irregular heart
between 1978 and 2015 reported low levels of calcium and phosphate, rhythm risk in older patients and lower
that vitamin D was sufficient in most and an increased parathyroid hormone incidence of heart attacks.
healthy South Africans. However, in response. This is detrimental to bone
among those lacking vitamin D, black health and causes bone loss that may Vitamin D is known to influence
South Africans were most affected at increase the risk of fractures. the immune system, especially the

24 Waterfall City Issue 3 2025