News

While there very likely are a host of social factors going into racial differences in outcomes, that this relates to stillbirth outcomes means there's another factor that needs to be considered in the mix too.

There was a pretty neat study this year looking at how national Vitamin D fortification programs in the food supply of Finland and Sweden and how those programs correlated with stillbirth before and after: Is there a relation between stillbirth and low levels of vitamin D in the population? A bi-national follow-up study of vitamin D fortification (2023).

Key point:

Our observational data of > 4 million pregnancies show that in two Northern countries with widespread low plasma vitamin D levels (< 50 nmol/l), each increment of national vitamin D food fortification was associated with an approximately 15% reduction in stillbirths.

This is relevant to the above study given the findings in Distribution of vitamin D status in the UK: a cross-sectional analysis of UK Biobank (2021):

Asian (n=4297/8000, 53.7%) and black (n=2459/7046, 34.9%) participants had a higher proportion of vitamin D deficiency than white participants (n=50 920/422 907, 12%).

It's worth noting that the picture is a bit more complicated, as there's studies that indicate that specifically for bone health and cardiovascular health that low Vitamin D serum levels don't necessarily mean deficiency for all populations, so a uniform watermark for deficiency for all people may not be the best approach.

But it's certainly possible that things like viral clearance rates or neonatal health are more dependent on Vitamin D than has been studied up until the past few years and that some of the racial differences between those outcomes (i.e. COVID response or stillbirths) is actually related to the levels of a vitamin that's fairly trivially supplemented.

It's a bit frustrating, as while it's understandable why scientists tend to avoid research focused on racial differences with a 10' pole, the key biological difference between white people and black or Indian people is going to be skin melanin and thus Vitamin D absorption. And in a society that's increasingly indoors and sun avoidant, that may be having serious health consequences on everyone but disproportionately negatively impacting minority communities.

We kind of need to grow the fuck up and be able to maintain both a commitment to decreasing differences in social treatment in medicine while simultaneously being willing to seriously look at biological differences to (a) identify ideal Vitamin D levels for different people with different biological factors and different circumstances (i.e. maternity health may need a different level than other periods of time), and (b) further look at how these differences may be responsible in part for racial disparities in standards of care.

If we only assume social differences and are unwilling to seriously look at other factors, it will lead to years of aimlessly pursuing measures to change outcomes that will continually fail while leaving people vulnerable to factors that can be fixed with something incredibly easy and cheap to improve.

So while the OP study difference in stillbirth outcomes is likely due to multiple factors, a 4x higher rate of potential deficiency in the UK for something linked to double digit decreases in stillbirth rates at each supplementation interval during national supplementation campaigns elsewhere seems like it shouldn't be ignored in thinking about possible ways to help improve outcomes here.