Sun’s rays make summer babies taller and stronger, study claims

Mothers who are pregnant in the summer have taller and stronger-boned babies because they benefit from sun’s vitamin-boosting rays, a new study has found.

Expectant mothers lucky enough to be blooming in the hot months should get enough sun to boost their vitamin D levels just by walking around outside or even sunbathing Photo: GETTY

Those born in the late summer and early autumn are around half a centimetre taller and have wider bones than their peers born in winter and spring, an 18 year project found.

Expectant mothers lucky enough to be blooming in the hot months should get enough sun to boost their vitamin D levels just by walking around outside or even sunbathing.

Sun exposure cancer warnings ‘lead to Vitamin D deficiencies’

Public health warnings about skin cancer have led to a rise in Vitamin D deficiency through lack of sunlight, according to a controversial study into the effects of ultraviolet exposure.

Vitamin D, produced by the body in response to sunlight, helps protect against cancer Photo: GETTYBut now, a controversial new study has blamed the same public health messages for causing growing numbers of people to suffer from vitamin D deficiency, because they are failing to get enough sunlight on their skin.

Vitamin D is produced by the body in response to exposure from ultraviolet radiation from natural sunlight. It helps protect against cancer and is also thought to be important in helping to prevent bone disease such as osteoporosis, as well as autoimmune diseases, asthma, diabetes, high blood pressure, depression, Parkinson’s disease and Multiple Sclerosis.

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The researchers are now calling for guidelines on sunlight exposure to be reviewed to ensure people receive enough vitamin D.

Dr Veronique Bataille, who led the study, said: “There has been so much effort put into telling people about the damaging effects of ultraviolet light from sunshine, many now take extreme measures to ensure they don’t get exposure by wearing moisturisers with factor 15 all year round.

“We don’t want to say that sunbathing is healthy as there is clearly a risk, but people do need a bit of sunshine to stay healthy.”

Dr Bataille and her colleagues measured vitamin D levels in the blood of 1,414 white women in the UK and compared this to their skin type and details about the number of foreign holidays, sunbed use and the number of times they had been sunburnt.

They found that those with the fairest skin, who usually have red or blonde hair, had the lowest levels of vitamin D.

Conventional scientific thinking suggests this should not be the case.

People with greater levels of melanin – which is the pigment which causes darker colour in skin – make less vitamin D and there is evidence to show that those with Asian and Afro-Caribbean backgrounds have trouble producing the vitamin.

Dr Bataille, a consultant dermatologist at Hemel Hempstead General Hospital and a researcher at Kings College London, also found that those with fair skin also had the lowest levels of sun exposure through the number of holidays they had abroad and sunbed use.

The researchers concluded that people with fair skin actively avoided sun exposure more, due to their increased sensitivity and so produced less vitamin D. They added, however, there may also be a genetic element that means people with fair skin metabolise vitamin D differently.

The findings come after another study by Dr Bataille’s group that showed sunlight may not be the main cause of melanoma, the most dangerous form of skin cancer. Instead they concluded that the number of moles on the skin was a better indicator of risk.

“The advice on sun exposure needs to be reviewed,” said Dr Bataille. “It is potentially harmful if people are getting the message that they should completely avoid the sun. The advice needs to be better tailored to the differences in skin type and sun levels around the country.”

Experts claim that excessive avoidance of the sun has stemmed from confusing official guidance on sun exposure which has unduly raised fears about the risk of being outside in the sunshine.

Advice on the Health Protection Agency’s website states that people should limit unprotected personal exposure to solar radiation, particularly during the four hours around midday, even in the UK. It even warns that sunburn can occur when in the shade or when cloudy.

Cancer Research UK used to advice that people stayed in the shade between 11am and 3pm, the time when the sun is at its hottest and the best time for making vitamin D according to experts. They recently changed their advice to “spend time in the shade between 11am and 3pm” and “aim to cover up”.

Vitamin D can be obtained from food, including oily fish and eggs, but it is harder for the body to obtain enough from these sources and consumption of these products in the UK has dramatically declined.

Dr Bataille believes people can make enough vitamin D from just 15 minutes exposure to sunlight while wearing a T-shirt, but added that this would need to be increased for those with dark skin or during the winter months when sunlight is lower.

According to a separate recent study at University College London, 20 per cent of women and 12 per cent of men are now classed as being clinically vitamin D deficient, while levels of the vitamin in nearly two thirds of women and 57 per cent of men are “insufficient”.

Dr Vasant Hirani, who led the study, added: “The advice on sun exposure does need to be clarified.”

The British Association of Dermatologists has recently issued guidance with the National Osteoporosis Society that recommends people get 15 to 20 minutes of sun exposure a day.

Nina Goad, from the Association, said she doubted public health messages were responsible for causing vitamin D deficiency.

“Vitamin D deficiency is likely to be due to our lifestyles meaning we spend a lot of time indoors, to a lack of vitamin D in our diets, and to our climate meaning we have limited sun exposure for much of the year,” she added.

A spokesman for the Health Protection Agency said: “We are not saying that people should avoid all sunlight. Indeed a small amount can help to maintain vitamin D levels.

“Sunbathing incurs the potential hazard without adding to vitamin D levels.”

Let the Sun Shine In (Especially When Pregnant)

Are you shorter than you had hoped or expected to be? Well, although genes play a large role in a person’s final adult height, new research suggests that the amount of sunlight that a woman is exposed to during her pregnancy may have a lot to do with it as well.

Researchers note that: Several recent studies have reported a causal association between stature and month of birth. Perinatal exposure to sunlight has been suggested as the principal factor underlying this relationship, although the mechanisms involved remain a matter of debate.

They analyzed the association of perinatal sunlight exposure to birth size and height at regular intervals all the way up to age 26.

“The findings confirmed that pre-natal sunlight is one of the most significant determinants of height,” conclude the researchers, although they are unsure of the trimester of greatest influence.

Early Human Development November 1, 2000; 60: 35-42

Pre-Birth Vitamin D Levels Determine Your Health for Life

by Kerri Knox, RN, citizen journalist

In the nature versus nurture debate, scientists often talk about genetics versus environmental factors in health. One environmental factor that has been getting a lot of attention lately is Vitamin D- and with good reason. Vitamin D is turning out to be a major influence in heart disease, cancer, diabetes and many other health problems.

But Vitamin D is even MORE vital than was previously thought. New research is showing that even our Pre-Birth vitamin d levels are an important determinant of our future health. When we speak of disease and health, we often think that people who are healthy are ‘lucky’ and people who are unhealthy as ‘unlucky’. But the debate is beginning to tip towards the fact that environmental factors influence genetics more than we can ever imagine, and luck of the genes has less to do with health than environmental factors.

Vitamin D as an environmental factor in our health is not debated, only HOW MUCH of a factor in our health is what is debated.

“Careful attention to maternal vitamin D status could translate into diverse improvements in health outcomes for the following generation”

Professor John McGrath Queensland Centre for Schizophrenia Research, Wolston Park Hospital, Wacol, Queensland, Australia

Vitamin D deficiency has long been associated with osteoporosis, but most of us think of osteoporosis as starting in older age. Since women are particularly affected, it’s often that vitamin d and calcium supplementation is begun after menopause to help prevent the associated fractures of osteoporosis.

But women in their pre-reproductive and reproductive years need to be supplemented too, less for themselves, but more for the health of their offspring.

Several studies have shown that pre-birth vitamin d levels can determine bone mass and risk of fracture as an adult! Disturbingly, vitamin d deficiency is rampant among pregnant women and it could be having devastating consequences on the youngest generations.

“Vitamin D supplementation of pregnant women, especially during winter months, could lead to long-lasting reductions in the risk of osteoporotic fracture in their offspring.”

‘Maternal vitamin D status during pregnancy and childhood bone mass at age 9 years: a longitudinal study’

Bone strength isn’t the only health issue that seems to be already determined by a mother’s intake of vitamin D, our mental health is also affected. Schizophrenia has long been associated with vitamin d levels due to its odd characteristic of occurring more frequently in those born in winter or early spring.

This association is not just coincidental; vitamin D levels in the womb affect the health of the baby, even much later in life. Even a child’s lungs are affected by a mother’s vitamin D levels. Asthma, a common childhood problem, has been linked to vitamin D deficiency in mothers. The Journal ‘Clinical and Experimental Allergy’ published an article entitled, ‘Childhood asthma is a fat-soluble vitamin deficiency disease.’ which outlines this strong link between vitamin D and childhood asthma.

Low Levels of Vitamin D Tied to Numerous Health Ailments, Studies Find

Men with low vitamin D levels are more likely to suffer heart attacks than men with healthy levels of the vitamin, according to a study released this week.

The finding, interesting on its own, is also the latest drop in what’s become a steady stream of news about the health effects of vitamin D — the sunlight-produced vitamin once known mainly for helping to prevent the bone disease rickets in children.

A study released in May, for example, found that women with breast cancer who had low vitamin D levels at the time of their diagnosis were 73 percent more likely to die from the disease, and nearly twice as likely to have it recur.

And over the past few years, researchers have linked low vitamin D levels to prostate cancer, colon cancer, multiple sclerosis, influenza and chronic muscle pain, among other maladies. How can one vitamin be linked to so many disparate diseases?

“Activated vitamin D is probably the oldest hormone on earth, phytoplankton that have existed for 750 million years [contain] it,” said vitamin D research Michael Holick, of Boston University. “Every cell and tissue in our body has a vitamin D receptor, and all use it for different purposes.”

Vitamin D is found in small amounts in a few foods, including fatty fish like salmon, as well as in milk and eggs. But mainly the human body produces its own vitamin D, triggered when the UVB rays in sunlight hit the skin.