Micronutrient deficiency is thought to affect a third of the world’s population and is particularly harmful on the developing foetus.
Children born with severe vitamin D deficiency often develop a variety of bone-related issues, including rickets.
Now Harvard researchers report on vitamin D’s ability to affect inflammatory signals that aid in the production of blood stem cells.
The research team discovered that when vitamin D supplementation was reduced, fewer cells were formed.
"What was surprising was that vitamin D is having an impact so early," said lead author Dr Trista North, a stem cell biologist at Harvard's Beth Israel Deaconess Medical Center.
"We really only thought about vitamin D in terms of bone development and maintenance, but we clearly show that, whether they were zebrafish or human blood stem cells, they can respond directly to the nutrient."
A major source of vitamin D is UV radiation, but many nations closer to the equator with higher sun exposure, have unacceptable deficiency levels.
This has led to a European Food Safety Authority (EFSA) panel setting an adequate intake (AI) level of 15 micrograms (µg) per day from food sources for adults and children to achieve a serum level of 50 nanomoles per litre (nmol / L).
For infants aged 7–11 months, 10 µg / day was established.
The levels have been criticised for being too low.
European countries such as Sweden are preparing to send proposals for mandatory vitamin D food fortification to the EU.
“This study for the first time elucidates a role of vitamin D3 in the process of hematopoietic stem and progenitor cell expansion,” said Dr Manfred Eggersdorfer, senior VP in nutrition science and advocacy at DSM DSM Nutritional Products.
“It demonstrates additional and new roles of vitamin D. The important impact of this finding is that inadequate or even deficient vitamin D status – which is found in many population groups - will impair cell expansion during embryogenesis.”
“This finding is in our view of major public interest. Based on this study it can be speculated that all ages benefit from an optimal vitamin D3 status, since hematopoiesis is life-long process.”
The subject of vitamin D supplementation during pregnancy was also up for discussion in a Danish study.
Here, the offspring of mothers who had a vitamin D2/D3 level in their umbilical blood over 25 nmol / L during pregnancy had fewer symptoms of Attention Deficit Hyperactivity Disorder (ADHD) at the age of 2½ years.
The study could offer no mechanism of action as to the vitamin’s mechanism of action in the onset of ADHD but evidence suggests vitamin D’s role in the early brain development was more significant than previously thought.
“There was no previous awareness that this link could be identified at such an early age,” said the study's research team, based at the University of Southern Denmark.
“It's impossible to say with which children will develop ADHD later on, but it will be interesting to further follow up those children who were at the highest end versus the normal range of the ADHD scale."
Vitamin D is a fat-soluble vitamin family encompassing ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Both forms are found in foods and supplements, while vitamin D3 is synthesised in the body when skin is exposed to UV light.
Mixed vitamin E findings
Another study found taking 50 mg of vitamin E per day could lower the risk of pneumonia in elderly male smokers.
Data collected in Finland between 1985-1993 and included 7,469 male smokers aged from 50 to 69 years, found that the vitamin lowered pneumonia risk by 35% in those men who had started smoking at a later age, at 21 years or older,
However, vitamin E had no effect on pneumonia for those who had started to smoke at a younger age.
“When people age, there is evidence of increased oxidative stress,” said Dr Harri Hemilä, lead study author from the Department of Public Health at the University of Helsinki. “Therefore it is reasonable to expect more evident effects for old people”.
The study made reference to the diversity of results that previous vitamin E findings produced. In certain subgroups of the study, vitamin E increased the risk of pneumonia, tuberculosis, the common cold, and even total mortality.
More relevant was the report that vitamin E actually increased the severity and symptoms of respiratory infections, fever during infections, and the restriction of activity caused by the infections.
“There are lots of laboratory findings about vitamin E and the immune system,” Hemilä commented. “Biology is complex and we should not expect same size effect for all people. Therefore, I would not propose any specific mechanism to explain the findings in my analysis.”
Source: Cell Reports
Published online ahead of print, doi.org/10.1016/j.celrep.2016.09.012
“Developmental Vitamin D availability impacts hematopoietic stem cell production.”
Authors: Trista North et al.
Source: The Australia & New Zealand Journal of Psychiatry
Published online ahead of print, doi.org/10.1177/0004867416670013
“Inverse associations between cord vitamin D and attention deficit hyperactivity disorder symptoms: A child cohort study.”
Authors: Niels Bilenberg et al.
Source: Clinical Interventions in Aging
Published online ahead of print, doi.org/10.2147/CIA.S114515
“Vitamin E administration may decrease the incidence of pneumonia in elderly males.”
Authors: Harri Hemilä