The Importance of VITAMIN D explained
From Maine to California, Florida to Washington State, its time to put away our winter boots and get our sandals on! Summer is nearly here and for many of us this means more time outdoors in the sunshine and the inevitable discussion of sunshine, sunscreen and vitamin D. How do we balance our physical need for vitamin D against potentially harmful ultraviolet rays from the Sun? Vitamin D is a vital nutrient related to bone health, cancer risk, cognitive function, inflammation regulation and immunity enhancement. The best source is the sun which is also the best source of skin cancer causing ultra violet (UV) rays. Vitamin D is created naturally in our body by converting UV rays into this nutrient or ingested either as a supplement or part of a nutritionally balanced diet.
Suntanning and tanning bed use are most the egregious culprits in skin cancers affecting nearly 5 million Americans each year. Most are not fatal but malignant melanomas affect 7000 people mostly 65 and older. White people have less melanin in their skin meaning less natural sun protection and have a 20x’s greater risk of melanoma than African Americans. (Melanin is the amino acid for pigment that gives human skin, hair and eyes their color. Some have more, some less. Freckles are small, concentrated areas of melanin.) The older we get the less able our bodies are to convert UV rays to Vitamin D. I need 3X’s the sun exposure as my grandson to produce the same amount of Vitamin D. Vitamin D deficiency is nearly universal with some populations affected more than others. A 2006 report found Americans overall to be 41% deficient but those numbers rose to 63% for Hispanic-Americans and 82% for African Americans. Higher levels of naturally occurring melanin may contribute as well as diet, exercise, climate and metabolism.
It is a fat-soluble vitamin found in some foods, added to other foods, available in supplement form or synthesized by UV rays hitting our skin. It promotes calcium and phosphorus absorption needed for bone growth, density and overall health. It protects older people from osteoporosis and young children from rickets (a softening and weakening of children’s’ bones due to a prolonged vitamin D deficiency). Vitamin D plays a role in the reduction of inflammation, neuromuscular and immune functions and glucose metabolism.
The typical American diet yields around 275 IU’s (International Units). The Daily Recommended Intake (DRI) is 600 for most and 800/day when you are over 70.
- Natural Food Sources; Fatty fish like trout, salmon, tuna and mackerel. Beef liver, eggs, cheese and portobello mushrooms are great sources.
- Fortified Foods: Animal milks, breakfast cereals, plant-based milks like soy, almond and oat as well as orange juice are all vitamin D fortified foods.
- Dietary Supplements: Active people in sunny climates usually produce most of the vitamin D they need from their sun exposure. Less active, housebound or older people especially in colder climates generally experience reduced vitamin D production and need to add supplements, most often in pill form. Some of us may recall or have heard about Cod Liver Oil famously used to dose children in the 1930’s. I remember this from Mary Poppins, and its use effectively eliminated childhood rickets in the US.
- Sun Exposure: Most everyone in the world gets some vitamin D from the sun. Seasons, time of day, cloud cover, smog, age, skin melanin levels and sunscreen use are all variables in sun exposure and the resulting vitamin D production.
Guidelines for sun exposure
5-30 minutes between 10am-4pm daily or minimally 2x’s/week is believed to be best practices for sufficient vitamin D synthesis. Ultraviolet radiation is a carcinogen and UV sun exposure is the most preventable cause of skin cancer so opinions, recommendations and advice vary. Sunscreen with a sun-protection-factor (SPF) of 8-15 is generally adequate however most of us either do not:
- Use it
- Cover all exposed skin
- Reapply regularly and frequently
UV rays do not penetrate glass so sitting inside in your favorite sunny spot may make you feel good but is useless for vitamin D synthesis. A further note about tanning beds. Don’t! The actress, Olivia Wilde has this to say regarding tanning beds, “In a thousand years, archeologists will dig up tanning beds and think we fried people as punishment.”
Who is at risk for vitamin D deficiency?
Deficiency means getting less than the minimum DRI of 400-600 IU’s. A 2013-16 National Health and Nutrition Examination Survey (NHANES) found that 92% of men and 97% of women ingested less than the DRI. Deficiency can vary by race, ethnicity and age.
- Breastfed infants: human breast milk provides less than optimal amounts of vitamin D because it is causally related to the vitamin D status of the mother. This is not an excuse to take your infant unprotected out into the sun. It can mean an infant supplement might be needed.
- Older Adults: They generally spend more time indoors and may have nutritionally inadequate diets. As we age, our skin’s ability to synthesize vitamin D diminishes.
- Limited Sun Exposure: This includes housebound people, those with occupations that never see the light of day and some religious populations with required skin coverings,
- Dark skinned individuals: As discussed previously, higher concentrations of melanin inhibit the skin’s ability to produce vitamin D from sunshine.
- Fat Absorption limitations: Medical conditions such as liver, celiac or Crohn’s disease, Cystic Fibrosis or ulcerative colitis are at risk populations. Vitamin D is fat-soluble and relies on digestion to absorb dietary fat.
- Obesity or Gastric Bypass: Those with a BMI (Body Mass Index) over 30 have greater difficulty synthesizing vitamin D. Bypass patients have the part of their small intestine known to be needed for vitamin D processing bypassed.
Bone health at any age. It helps regulate inflammation. It is inconclusive as a cancer preventative, but adequate daily amounts may reduce mortality. Vitamin D deficiency is associated with vascular dysfunction, arterial stiffening, hypertrophy of the left heart ventricle and hyperlipidemia. There is promising data linking vitamin D to helping alleviate depression as well as management of multiple sclerosis and type 2 diabetes. There is no evidence that vitamin D supplements aid in weight loss.
Getting regular doses of sunshine makes a lot of sense but as with anything, moderation is key. Our skin has a UV ray saturation point where it stops synthesizing vitamin D. Supplement doses in excess of 1000 IU’s/day can result in bone loss. Sunlight can be more friend than foe. Be sensible, use sunscreen and ask your healthcare provider if you need vitamin D testing.
NHS Solutions has interim healthcare leaders in food and nutrition services available. Contact us if your organization requires a specialist in this or any other healthcare leadership specialty. NHS Solutions is able to quickly assess and match the right candidate to a hospital’s need. We are usually able to present qualified candidates within 24 hours for consideration.